3749 Commits

Author SHA1 Message Date
Dan Carpenter
cb283cca1d rtc: mc146818-lib: fix signedness bug in mc146818_get_time()
[ Upstream commit 7372971c1be5b7d4fdd8ad237798bdc1d1d54162 ]

The mc146818_get_time() function returns zero on success or negative
a error code on failure.  It needs to be type int.

Fixes: d35786b3a28d ("rtc: mc146818-lib: change return values of mc146818_get_time()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220111071922.GE11243@kili
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Mateusz Jończyk
5c432383b6 rtc: mc146818-lib: fix locking in mc146818_set_time
[ Upstream commit 811f5559270f25c34c338d6eaa2ece2544c3d3bd ]

In mc146818_set_time(), CMOS_READ(RTC_CONTROL) was performed without the
rtc_lock taken, which is required for CMOS accesses. Fix this.

Nothing in kernel modifies RTC_DM_BINARY, so a separate critical section
is allowed here.

Fixes: dcf257e92622 ("rtc: mc146818: Reduce spinlock section in mc146818_set_time()")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220220090403.153928-1-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Chris Wilson
5e26531d81 rtc: cmos: Disable irq around direct invocation of cmos_interrupt()
[ Upstream commit 13be2efc390acd2a46a69a359f6efc00ca434599 ]

As previously noted in commit 66e4f4a9cc38 ("rtc: cmos: Use
spin_lock_irqsave() in cmos_interrupt()"):

<4>[  254.192378] WARNING: inconsistent lock state
<4>[  254.192384] 5.12.0-rc1-CI-CI_DRM_9834+ #1 Not tainted
<4>[  254.192396] --------------------------------
<4>[  254.192400] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4>[  254.192409] rtcwake/5309 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4>[  254.192429] ffffffff8263c5f8 (rtc_lock){?...}-{2:2}, at: cmos_interrupt+0x18/0x100
<4>[  254.192481] {IN-HARDIRQ-W} state was registered at:
<4>[  254.192488]   lock_acquire+0xd1/0x3d0
<4>[  254.192504]   _raw_spin_lock+0x2a/0x40
<4>[  254.192519]   cmos_interrupt+0x18/0x100
<4>[  254.192536]   rtc_handler+0x1f/0xc0
<4>[  254.192553]   acpi_ev_fixed_event_detect+0x109/0x13c
<4>[  254.192574]   acpi_ev_sci_xrupt_handler+0xb/0x28
<4>[  254.192596]   acpi_irq+0x13/0x30
<4>[  254.192620]   __handle_irq_event_percpu+0x43/0x2c0
<4>[  254.192641]   handle_irq_event_percpu+0x2b/0x70
<4>[  254.192661]   handle_irq_event+0x2f/0x50
<4>[  254.192680]   handle_fasteoi_irq+0x9e/0x150
<4>[  254.192693]   __common_interrupt+0x76/0x140
<4>[  254.192715]   common_interrupt+0x96/0xc0
<4>[  254.192732]   asm_common_interrupt+0x1e/0x40
<4>[  254.192750]   _raw_spin_unlock_irqrestore+0x38/0x60
<4>[  254.192767]   resume_irqs+0xba/0xf0
<4>[  254.192786]   dpm_resume_noirq+0x245/0x3d0
<4>[  254.192811]   suspend_devices_and_enter+0x230/0xaa0
<4>[  254.192835]   pm_suspend.cold.8+0x301/0x34a
<4>[  254.192859]   state_store+0x7b/0xe0
<4>[  254.192879]   kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.192899]   new_sync_write+0x11d/0x1b0
<4>[  254.192916]   vfs_write+0x265/0x390
<4>[  254.192933]   ksys_write+0x5a/0xd0
<4>[  254.192949]   do_syscall_64+0x33/0x80
<4>[  254.192965]   entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.192986] irq event stamp: 43775
<4>[  254.192994] hardirqs last  enabled at (43775): [<ffffffff81c00c42>] asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193023] hardirqs last disabled at (43774): [<ffffffff81aa691a>] sysvec_apic_timer_interrupt+0xa/0xb0
<4>[  254.193049] softirqs last  enabled at (42548): [<ffffffff81e00342>] __do_softirq+0x342/0x48e
<4>[  254.193074] softirqs last disabled at (42543): [<ffffffff810b45fd>] irq_exit_rcu+0xad/0xd0
<4>[  254.193101]
                  other info that might help us debug this:
<4>[  254.193107]  Possible unsafe locking scenario:

<4>[  254.193112]        CPU0
<4>[  254.193117]        ----
<4>[  254.193121]   lock(rtc_lock);
<4>[  254.193137]   <Interrupt>
<4>[  254.193142]     lock(rtc_lock);
<4>[  254.193156]
                   *** DEADLOCK ***

<4>[  254.193161] 6 locks held by rtcwake/5309:
<4>[  254.193174]  #0: ffff888104861430 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x5a/0xd0
<4>[  254.193232]  #1: ffff88810f823288 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xe7/0x1c0
<4>[  254.193282]  #2: ffff888100cef3c0 (kn->active#285
<7>[  254.192706] i915 0000:00:02.0: [drm:intel_modeset_setup_hw_state [i915]] [CRTC:51:pipe A] hw state readout: disabled
<4>[  254.193307] ){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xf0/0x1c0
<4>[  254.193333]  #3: ffffffff82649fa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold.8+0xce/0x34a
<4>[  254.193387]  #4: ffffffff827a2108 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x47/0x70
<4>[  254.193433]  #5: ffff8881019ea178 (&dev->mutex){....}-{3:3}, at: device_resume+0x68/0x1e0
<4>[  254.193485]
                  stack backtrace:
<4>[  254.193492] CPU: 1 PID: 5309 Comm: rtcwake Not tainted 5.12.0-rc1-CI-CI_DRM_9834+ #1
<4>[  254.193514] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019
<4>[  254.193524] Call Trace:
<4>[  254.193536]  dump_stack+0x7f/0xad
<4>[  254.193567]  mark_lock.part.47+0x8ca/0xce0
<4>[  254.193604]  __lock_acquire+0x39b/0x2590
<4>[  254.193626]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193660]  lock_acquire+0xd1/0x3d0
<4>[  254.193677]  ? cmos_interrupt+0x18/0x100
<4>[  254.193716]  _raw_spin_lock+0x2a/0x40
<4>[  254.193735]  ? cmos_interrupt+0x18/0x100
<4>[  254.193758]  cmos_interrupt+0x18/0x100
<4>[  254.193785]  cmos_resume+0x2ac/0x2d0
<4>[  254.193813]  ? acpi_pm_set_device_wakeup+0x1f/0x110
<4>[  254.193842]  ? pnp_bus_suspend+0x10/0x10
<4>[  254.193864]  pnp_bus_resume+0x5e/0x90
<4>[  254.193885]  dpm_run_callback+0x5f/0x240
<4>[  254.193914]  device_resume+0xb2/0x1e0
<4>[  254.193942]  ? pm_dev_err+0x25/0x25
<4>[  254.193974]  dpm_resume+0xea/0x3f0
<4>[  254.194005]  dpm_resume_end+0x8/0x10
<4>[  254.194030]  suspend_devices_and_enter+0x29b/0xaa0
<4>[  254.194066]  pm_suspend.cold.8+0x301/0x34a
<4>[  254.194094]  state_store+0x7b/0xe0
<4>[  254.194124]  kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.194151]  new_sync_write+0x11d/0x1b0
<4>[  254.194183]  vfs_write+0x265/0x390
<4>[  254.194207]  ksys_write+0x5a/0xd0
<4>[  254.194232]  do_syscall_64+0x33/0x80
<4>[  254.194251]  entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.194274] RIP: 0033:0x7f07d79691e7
<4>[  254.194293] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
<4>[  254.194312] RSP: 002b:00007ffd9cc2c768 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[  254.194337] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f07d79691e7
<4>[  254.194352] RDX: 0000000000000004 RSI: 0000556ebfc63590 RDI: 000000000000000b
<4>[  254.194366] RBP: 0000556ebfc63590 R08: 0000000000000000 R09: 0000000000000004
<4>[  254.194379] R10: 0000556ebf0ec2a6 R11: 0000000000000246 R12: 0000000000000004

which breaks S3-resume on fi-kbl-soraka presumably as that's slow enough
to trigger the alarm during the suspend.

Fixes: 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
References: 66e4f4a9cc38 ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"):
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Xiaofei Tan <tanxiaofei@huawei.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210305122140.28774-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:59 +01:00
Thomas Gleixner
db44a9443e rtc: mc146818: Reduce spinlock section in mc146818_set_time()
[ Upstream commit dcf257e92622ba0e25fdc4b6699683e7ae67e2a1 ]

No need to hold the lock and disable interrupts for doing math.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.709243630@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Xiaofei Tan
17293d630f rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
[ Upstream commit 6950d046eb6eabbc271fda416460c05f7a85698a ]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1612355981-6764-2-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
acfd8ef683 rtc: cmos: avoid UIP when reading alarm time
[ Upstream commit cdedc45c579faf8cc6608d3ef81576ee0d512aa4 ]

Some Intel chipsets disconnect the time and date RTC registers when the
clock update is in progress: during this time reads may return bogus
values and writes fail silently. This includes the RTC alarm registers.
[1]

cmos_read_alarm() did not take account for that, which caused alarm time
reads to sometimes return bogus values. This can be shown with a test
patch that I am attaching to this patch series.

Fix this, by using mc146818_avoid_UIP().

[1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...]
Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006)
Page 208
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf
        "If a RAM read from the ten time and date bytes is attempted
        during an update cycle, the value read do not necessarily
        represent the true contents of those locations. Any RAM writes
        under the same conditions are ignored."

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-9-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
949bae0282 rtc: cmos: avoid UIP when writing alarm time
[ Upstream commit cd17420ebea580c22dd3a93f7237de3d2cfafc37 ]

Some Intel chipsets disconnect the time and date RTC registers when the
clock update is in progress: during this time reads may return bogus
values and writes fail silently. This includes the RTC alarm registers.
[1]

cmos_set_alarm() did not take account for that, fix it.

[1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...]
Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006)
Page 208
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf
        "If a RAM read from the ten time and date bytes is attempted
        during an update cycle, the value read do not necessarily
        represent the true contents of those locations. Any RAM writes
        under the same conditions are ignored."

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-10-mat.jonczyk@o2.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
33ac73a41a rtc: mc146818-lib: extract mc146818_avoid_UIP
[ Upstream commit ec5895c0f2d87b9bf4185db1915e40fa6fcfc0ac ]

Function mc146818_get_time() contains an elaborate mechanism of reading
the RTC time while no RTC update is in progress. It turns out that
reading the RTC alarm clock also requires avoiding the RTC update.
Therefore, the mechanism in mc146818_get_time() should be reused - so
extract it into a separate function.

The logic in mc146818_avoid_UIP() is same as in mc146818_get_time()
except that after every

        if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) {

there is now "mdelay(1)".

To avoid producing a very unreadable patch, mc146818_get_time() will be
refactored to use mc146818_avoid_UIP() in the next patch.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-6-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
8bb5fe5830 rtc: mc146818-lib: fix RTC presence check
[ Upstream commit ea6fa4961aab8f90a8aa03575a98b4bda368d4b6 ]

To prevent an infinite loop in mc146818_get_time(),
commit 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
added a check for RTC availability. Together with a later fix, it
checked if bit 6 in register 0x0d is cleared.

This, however, caused a false negative on a motherboard with an AMD
SB710 southbridge; according to the specification [1], bit 6 of register
0x0d of this chipset is a scratchbit. This caused a regression in Linux
5.11 - the RTC was determined broken by the kernel and not used by
rtc-cmos.c [3]. This problem was also reported in Fedora [4].

As a better alternative, check whether the UIP ("Update-in-progress")
bit is set for longer then 10ms. If that is the case, then apparently
the RTC is either absent (and all register reads return 0xff) or broken.
Also limit the number of loop iterations in mc146818_get_time() to 10 to
prevent an infinite loop there.

The functions mc146818_get_time() and mc146818_does_rtc_work() will be
refactored later in this patch series, in order to fix a separate
problem with reading / setting the RTC alarm time. This is done so to
avoid a confusion about what is being fixed when.

In a previous approach to this problem, I implemented a check whether
the RTC_HOURS register contains a value <= 24. This, however, sometimes
did not work correctly on my Intel Kaby Lake laptop. According to
Intel's documentation [2], "the time and date RAM locations (0-9) are
disconnected from the external bus" during the update cycle so reading
this register without checking the UIP bit is incorrect.

[1] AMD SB700/710/750 Register Reference Guide, page 308,
https://developer.amd.com/wordpress/media/2012/10/43009_sb7xx_rrg_pub_1.00.pdf

[2] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet
Volume 1 of 2, page 209
Intel's Document Number: 334658-006,
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf

[3] Functions in arch/x86/kernel/rtc.c apparently were using it.

[4] https://bugzilla.redhat.com/show_bug.cgi?id=1936688

Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
Fixes: ebb22a059436 ("rtc: mc146818: Dont test for bit 0-5 in Register D")
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-5-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:56 +01:00
Mateusz Jończyk
775d4661f1 rtc: Check return value from mc146818_get_time()
[ Upstream commit 0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9 ]

There are 4 users of mc146818_get_time() and none of them was checking
the return value from this function. Change this.

Print the appropriate warnings in callers of mc146818_get_time() instead
of in the function mc146818_get_time() itself, in order not to add
strings to rtc-mc146818-lib.c, which is kind of a library.

The callers of alpha_rtc_read_time() and cmos_read_time() may use the
contents of (struct rtc_time *) even when the functions return a failure
code. Therefore, set the contents of (struct rtc_time *) to 0x00,
which looks more sensible then 0xff and aligns with the (possibly
stale?) comment in cmos_read_time:

	/*
	 * If pm_trace abused the RTC for storage, set the timespec to 0,
	 * which tells the caller that this RTC value is unusable.
	 */

For consistency, do this in mc146818_get_time().

Note: hpet_rtc_interrupt() may call mc146818_get_time() many times a
second. It is very unlikely, though, that the RTC suddenly stops
working and mc146818_get_time() would consistently fail.

Only compile-tested on alpha.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-alpha@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-4-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Mateusz Jończyk
b9a5c470e0 rtc: mc146818-lib: change return values of mc146818_get_time()
[ Upstream commit d35786b3a28dee20b12962ae2dd365892a99ed1a ]

No function is checking mc146818_get_time() return values yet, so
correct them to make them more customary.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-3-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Mateusz Jończyk
94eaf9966e rtc: cmos: remove stale REVISIT comments
[ Upstream commit e1aba37569f0aa9c993f740828871e48eea79f98 ]

It appears mc146818_get_time() and mc146818_set_time() now correctly
use the century register as specified in the ACPI FADT table. It is not
clear what else could be done here.

These comments were introduced by
        commit 7be2c7c96aff ("[PATCH] RTC framework driver for CMOS RTCs")
in 2007, which originally referenced function get_rtc_time() in
include/asm-generic/rtc.h .

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210716210437.29622-1-mat.jonczyk@o2.pl
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
f5b51f8550 rtc: mc146818: Dont test for bit 0-5 in Register D
[ Upstream commit ebb22a05943666155e6da04407cc6e913974c78c ]

The recent change to validate the RTC turned out to be overly tight.

While it cures the problem on the reporters machine it breaks machines
with Intel chipsets which use bit 0-5 of the D register. So check only
for bit 6 being 0 which is the case on these Intel machines as well.

Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs")
Reported-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Reported-by: Dirk Gouders <dirk@gouders.net>
Reported-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Dirk Gouders <dirk@gouders.net>
Tested-by: Len Brown <len.brown@intel.com>
Tested-by: Borislav Petkov <bp@suse.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/87zh0nbnha.fsf@nanos.tec.linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
3736972360 rtc: mc146818: Detect and handle broken RTCs
[ Upstream commit 211e5db19d15a721b2953ea54b8f26c2963720eb ]

The recent fix for handling the UIP bit unearthed another issue in the RTC
code. If the RTC is advertised but the readout is straight 0xFF because
it's not available, the old code just proceeded with crappy values, but the
new code hangs because it waits for the UIP bit to become low.

Add a sanity check in the RTC CMOS probe function which reads the RTC_VALID
register (Register D) which should have bit 0-6 cleared. If that's not the
case then fail to register the CMOS.

Add the same check to mc146818_get_time(), warn once when the condition
is true and invalidate the rtc_time data.

Reported-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/87tur3fx7w.fsf@nanos.tec.linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Thomas Gleixner
7c7075c88d rtc: mc146818: Prevent reading garbage
[ Upstream commit 05a0302c35481e9b47fb90ba40922b0a4cae40d8 ]

The MC146818 driver is prone to read garbage from the RTC. There are
several issues all related to the update cycle of the MC146818. The chip
increments seconds obviously once per second and indicates that by a bit in
a register. The bit goes high 244us before the actual update starts. During
the update the readout of the time values is undefined.

The code just checks whether the update in progress bit (UIP) is set before
reading the clock. If it's set it waits arbitrary 20ms before retrying,
which is ample because the maximum update time is ~2ms.

But this check does not guarantee that the UIP bit goes high and the actual
update happens during the readout. So the following can happen

 0.997 	       UIP = False
   -> Interrupt/NMI/preemption
 0.998	       UIP -> True
 0.999	       Readout	<- Undefined

To prevent this rework the code so it checks UIP before and after the
readout and if set after the readout try again.

But that's not enough to cover the following:

 0.997 	       UIP = False
 	       Readout seconds
   -> NMI (or vCPU scheduled out)
 0.998	       UIP -> True
 	       update completes
	       UIP -> False
 1.000	       Readout	minutes,....
 	       UIP check succeeds

That can make the readout wrong up to 59 seconds.

To prevent this, read the seconds value before the first UIP check,
validate it after checking UIP and after reading out the rest.

It's amazing that the original i386 code had this actually correct and
the generic implementation of the MC146818 driver got it wrong in 2002 and
it stayed that way until today.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.594826678@linutronix.de
Stable-dep-of: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:31:55 +01:00
Yang Yingliang
82bfea344e rtc: mt6397: check return value after calling platform_get_resource()
[ Upstream commit d3b43eb505bffb8e4cdf6800c15660c001553fe6 ]

It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.

Fixes: fc2979118f3f ("rtc: mediatek: Add MT6397 RTC driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220505125043.1594771-1-yangyingliang@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:33 +02:00
Mario Limonciello
00d8b06a4e rtc: mc146818-lib: Fix the AltCentury for AMD platforms
[ Upstream commit 3ae8fd41573af4fb3a490c9ed947fc936ba87190 ]

Setting the century forward has been failing on AMD platforms.
There was a previous attempt at fixing this for family 0x17 as part of
commit 7ad295d5196a ("rtc: Fix the AltCentury value on AMD/Hygon
platform") but this was later reverted due to some problems reported
that appeared to stem from an FW bug on a family 0x17 desktop system.

The same comments mentioned in the previous commit continue to apply
to the newer platforms as well.

```
MC146818 driver use function mc146818_set_time() to set register
RTC_FREQ_SELECT(RTC_REG_A)'s bit4-bit6 field which means divider stage
reset value on Intel platform to 0x7.

While AMD/Hygon RTC_REG_A(0Ah)'s bit4 is defined as DV0 [Reference]:
DV0 = 0 selects Bank 0, DV0 = 1 selects Bank 1. Bit5-bit6 is defined
as reserved.

DV0 is set to 1, it will select Bank 1, which will disable AltCentury
register(0x32) access. As UEFI pass acpi_gbl_FADT.century 0x32
(AltCentury), the CMOS write will be failed on code:
CMOS_WRITE(century, acpi_gbl_FADT.century).

Correct RTC_REG_A bank select bit(DV0) to 0 on AMD/Hygon CPUs, it will
enable AltCentury(0x32) register writing and finally setup century as
expected.
```

However in closer examination the change previously submitted was also
modifying bits 5 & 6 which are declared reserved in the AMD documentation.
So instead modify just the DV0 bank selection bit.

Being cognizant that there was a failure reported before, split the code
change out to a static function that can also be used for exclusions if
any regressions such as Mikhail's pop up again.

Cc: Jinke Fan <fanjinke@hygon.cn>
Cc: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/all/CABXGCsMLob0DC25JS8wwAYydnDoHBSoMh2_YLPfqm3TTvDE-Zw@mail.gmail.com/
Link: https://www.amd.com/system/files/TechDocs/51192_Bolton_FCH_RRG.pdf
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220111225750.1699-1-mario.limonciello@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:54 +02:00
Andre Przywara
703c80ff43 rtc: sun6i: Fix time overflow handling
[ Upstream commit 9f6cd82eca7e91a0d0311242a87c6aa3c2737968 ]

Using "unsigned long" for UNIX timestamps is never a good idea, and
comparing the value of such a variable against U32_MAX does not do
anything useful on 32-bit systems.

Use the proper time64_t type when dealing with timestamps, and avoid
cutting down the time range unnecessarily. This also fixes the flawed
check for the alarm time being too far into the future.

The check for this condition is actually somewhat theoretical, as the
RTC counts till 2033 only anyways, and 2^32 seconds from now is not
before the year 2157 - at which point I hope nobody will be using this
hardware anymore.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220211122643.1343315-4-andre.przywara@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:53 +02:00
Hugo Villeneuve
c39b91fcd5 rtc: pcf2127: fix bug when reading alarm registers
[ Upstream commit 73ce05302007eece23a6acb7dc124c92a2209087 ]

The first bug is that reading the 5 alarm registers results in a read
operation of 20 bytes. The reason is because the destination buffer is
defined as an array of "unsigned int", and we use the sizeof()
operator on this array to define the bulk read count.

The second bug is that the read value is invalid, because we are
indexing the destination buffer as integers (4 bytes), instead of
indexing it as u8.

Changing the destination buffer type to u8 fixes both problems.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220208162908.3182581-1-hugo@hugovil.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:52 +02:00
Vincent Whitchurch
2b4e5a2d7d rtc: fix use-after-free on device removal
[ Upstream commit c8fa17d9f08a448184f03d352145099b5beb618e ]

If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work().  Cleanup the
timerqueue and ensure the work is stopped to fix this.

 BUG: KASAN: use-after-free in mutex_lock+0x94/0x110
 Write of size 8 at addr ffffff801d846338 by task kworker/3:1/41

 Workqueue: events rtc_timer_do_work
 Call trace:
  mutex_lock+0x94/0x110
  rtc_timer_do_work+0xec/0x630
  process_one_work+0x5fc/0x1344
  ...

 Allocated by task 551:
  kmem_cache_alloc_trace+0x384/0x6e0
  devm_rtc_allocate_device+0xf0/0x574
  devm_rtc_device_register+0x2c/0x12c
  ...

 Freed by task 572:
  kfree+0x114/0x4d0
  rtc_device_release+0x64/0x80
  device_release+0x8c/0x1f4
  kobject_put+0x1c4/0x4b0
  put_device+0x20/0x30
  devm_rtc_release_device+0x1c/0x30
  devm_action_release+0x54/0x90
  release_nodes+0x124/0x310
  devres_release_group+0x170/0x240
  i2c_device_remove+0xd8/0x314
  ...

 Last potentially related work creation:
  insert_work+0x5c/0x330
  queue_work_on+0xcc/0x154
  rtc_set_time+0x188/0x5bc
  rtc_dev_ioctl+0x2ac/0xbd0
  ...

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210160951.7718-1-vincent.whitchurch@axis.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:52 +02:00
Jiasheng Jiang
2e52a29470 rtc: wm8350: Handle error for wm8350_register_irq
[ Upstream commit 43f0269b6b89c1eec4ef83c48035608f4dcdd886 ]

As the potential failure of the wm8350_register_irq(),
it should be better to check it and return error if fails.
Also, it need not free 'wm_rtc->rtc' since it will be freed
automatically.

Fixes: 077eaf5b40ec ("rtc: rtc-wm8350: add support for WM8350 RTC")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220303085030.291793-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 21:00:54 +02:00
Tom Rix
33c204266c rtc: check if __rtc_read_time was successful
commit 915593a7a663b2ad08b895a5f3ba8b19d89d4ebf upstream.

Clang static analysis reports this issue
interface.c:810:8: warning: Passed-by-value struct
  argument contains uninitialized data
  now = rtc_tm_to_ktime(tm);
      ^~~~~~~~~~~~~~~~~~~

tm is set by a successful call to __rtc_read_time()
but its return status is not checked.  Check if
it was successful before setting the enabled flag.
Move the decl of err to function scope.

Fixes: 2b2f5ff00f63 ("rtc: interface: ignore expired timers when enqueuing new timers")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220326194236.2916310-1-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:40:40 +02:00
Uwe Kleine-König
e4c777fd8c amba: Make the remove callback return void
[ Upstream commit 3fd269e74f2feec973f45ee11d822faeda4fe284 ]

All amba drivers return 0 in their remove callback. Together with the
driver core ignoring the return value anyhow, it doesn't make sense to
return a value here.

Change the remove prototype to return void, which makes it explicit that
returning an error value doesn't work as expected. This simplifies changing
the core remove callback to return void, too.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # for drivers/memory
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> # for hwtracing/coresight
Acked-By: Vinod Koul <vkoul@kernel.org> # for dmaengine
Acked-by: Guenter Roeck <linux@roeck-us.net> # for watchdog
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Takashi Iwai <tiwai@suse.de> # for sound
Acked-by: Vladimir Zapolskiy <vz@mleia.com> # for memory/pl172
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210126165835.687514-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:02 +02:00
Riwen Lu
460aa9d873 rtc: cmos: Evaluate century appropriate
commit ff164ae39b82ee483b24579c8e22a13a8ce5bd04 upstream.

There's limiting the year to 2069. When setting the rtc year to 2070,
reading it returns 1970. Evaluate century starting from 19 to count the
correct year.

$ sudo date -s 20700106
Mon 06 Jan 2070 12:00:00 AM CST
$ sudo hwclock -w
$ sudo hwclock -r
1970-01-06 12:00:49.604968+08:00

Fixes: 2a4daadd4d3e5071 ("rtc: cmos: ignore bogus century byte")

Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
Acked-by: Eric Wong <e@80x24.org>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220106084609.1223688-1-luriwen@kylinos.cn
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> # preparation for stable
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:30:39 +01:00
Laurence de Bruxelles
c736ec01a2 rtc: pxa: fix null pointer dereference
commit 34127b3632b21e5c391756e724b1198eb9917981 upstream.

With the latest stable kernel versions the rtc on the PXA based
Zaurus does not work, when booting I see the following kernel messages:

pxa-rtc pxa-rtc: failed to find rtc clock source
pxa-rtc pxa-rtc: Unable to init SA1100 RTC sub-device
pxa-rtc: probe of pxa-rtc failed with error -2
hctosys: unable to open rtc device (rtc0)

I think this is because commit f2997775b111 ("rtc: sa1100: fix possible
race condition") moved the allocation of the rtc_device struct out of
sa1100_rtc_init and into sa1100_rtc_probe. This means that pxa_rtc_probe
also needs to do allocation for the rtc_device struct, otherwise
sa1100_rtc_init will try to dereference a null pointer. This patch adds
that allocation by copying how sa1100_rtc_probe in
drivers/rtc/rtc-sa1100.c does it; after the IRQs are set up a managed
rtc_device is allocated.

I've tested this patch with `qemu-system-arm -machine akita` and with a
real Zaurus SL-C1000 applied to 4.19, 5.4, and 5.10.

Signed-off-by: Laurence de Bruxelles <lfdebrux@gmail.com>
Fixes: f2997775b111 ("rtc: sa1100: fix possible race condition")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220101154149.12026-1-lfdebrux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:54:33 +01:00
Mateusz Jończyk
1da0b1cd42 rtc: cmos: take rtc_lock while reading from CMOS
commit 454f47ff464325223129b9b5b8d0b61946ec704d upstream.

Reading from the CMOS involves writing to the index register and then
reading from the data register. Therefore access to the CMOS has to be
serialized with rtc_lock. This invocation of CMOS_READ was not
serialized, which could cause trouble when other code is accessing CMOS
at the same time.

Use spin_lock_irq() like the rest of the function.

Nothing in kernel modifies the RTC_DM_BINARY bit, so there could be a
separate pair of spin_lock_irq() / spin_unlock_irq() before doing the
math.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-2-mat.jonczyk@o2.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:53:42 +01:00
Dan Carpenter
038dfd67d3 rtc: rv3032: fix error handling in rv3032_clkout_set_rate()
[ Upstream commit c3336b8ac6091df60a5c1049a8c685d0b947cc61 ]

Do not call rv3032_exit_eerd() if the enter function fails but don't
forget to call the exit when the enter succeeds.

Fixes: 2eeaa532acca ("rtc: rv3032: Add a driver for Microcrystal RV-3032")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211012101028.GT2083@kadam
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:23 +01:00
Yu-Tung Chang
647c19bc61 rtc: rx8010: select REGMAP_I2C
[ Upstream commit 0c45d3e24ef3d3d87c5e0077b8f38d1372af7176 ]

The rtc-rx8010 uses the I2C regmap but doesn't select it in Kconfig so
depending on the configuration the build may fail. Fix it.

Signed-off-by: Yu-Tung Chang <mtwget@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210830052532.40356-1-mtwget@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:02 +02:00
Dmitry Osipenko
ebedb252a4 rtc: tps65910: Correct driver module alias
commit 8d448fa0a8bb1c8d94eef7647edffe9ac81a281e upstream.

The TPS65910 RTC driver module doesn't auto-load because of the wrong
module alias that doesn't match the device name, fix it.

Cc: stable@vger.kernel.org
Reported-by: Anton Bambura <jenneron@protonmail.com>
Tested-by: Anton Bambura <jenneron@protonmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210808160030.8556-1-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18 13:40:05 +02:00
Krzysztof Kozlowski
cdb995a6cb rtc: max77686: Do not enforce (incorrect) interrupt trigger type
[ Upstream commit 742b0d7e15c333303daad4856de0764f4bc83601 ]

Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 77686 datasheet describes the interrupt line as active low
with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races.  With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210526172036.183223-6-krzysztof.kozlowski@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25 14:36:16 +02:00
Bixuan Cui
27582c9fa2 rtc: mxc_v2: add missing MODULE_DEVICE_TABLE
[ Upstream commit 206e04ec7539e7bfdde9aa79a7cde656c9eb308e ]

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210508031509.53735-1-cuibixuan@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25 14:36:12 +02:00
Dan Carpenter
ab4d76eb77 rtc: fix snprintf() checking in is_rtc_hctosys()
[ Upstream commit 54b909436ede47e0ee07f1765da27ec2efa41e84 ]

The scnprintf() function silently truncates the printf() and returns
the number bytes that it was able to copy (not counting the NUL
terminator).  Thus, the highest value it can return here is
"NAME_SIZE - 1" and the overflow check is dead code.  Fix this by
using the snprintf() function which returns the number of bytes that
would have been copied if there was enough space and changing the
condition from "> NAME_SIZE" to ">= NAME_SIZE".

Fixes: 92589c986b33 ("rtc-proc: permit the /proc/driver/rtc device to use other devices")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/YJov/pcGmhLi2pEl@mwanda
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:05:55 +02:00
Martin Fuzzey
a6f7bf2652 rtc: stm32: Fix unbalanced clk_disable_unprepare() on probe error path
commit 950ac33dbe6ff656a623d862022f0762ec061ba7 upstream.

The STM32MP1 RTC may have 2 clocks, the pclk and the rtc_ck.

If clk_prepare_enable() fails for the second clock (rtc_ck) we must only
call clk_disable_unprepare() for the first clock (pclk) but currently we
call it on both leading to a WARN:

[   15.629568] WARNING: CPU: 0 PID: 146 at drivers/clk/clk.c:958 clk_core_disable+0xb0/0xc8
[   15.637620] ck_rtc already disabled
[   15.663322] CPU: 0 PID: 146 Comm: systemd-udevd Not tainted 5.4.77-pknbsp-svn5759-atag-v5.4.77-204-gea4235203137-dirty #2413
[   15.674510] Hardware name: STM32 (Device Tree Support)
[   15.679658] [<c0111148>] (unwind_backtrace) from [<c010c0b8>] (show_stack+0x10/0x14)
[   15.687371] [<c010c0b8>] (show_stack) from [<c0ab3d28>] (dump_stack+0xc0/0xe0)
[   15.694574] [<c0ab3d28>] (dump_stack) from [<c012360c>] (__warn+0xc8/0xf0)
[   15.701428] [<c012360c>] (__warn) from [<c0123694>] (warn_slowpath_fmt+0x60/0x94)
[   15.708894] [<c0123694>] (warn_slowpath_fmt) from [<c053b518>] (clk_core_disable+0xb0/0xc8)
[   15.717230] [<c053b518>] (clk_core_disable) from [<c053c190>] (clk_core_disable_lock+0x18/0x24)
[   15.725924] [<c053c190>] (clk_core_disable_lock) from [<bf0adc44>] (stm32_rtc_probe+0x124/0x5e4 [rtc_stm32])
[   15.735739] [<bf0adc44>] (stm32_rtc_probe [rtc_stm32]) from [<c05f7d4c>] (platform_drv_probe+0x48/0x98)
[   15.745095] [<c05f7d4c>] (platform_drv_probe) from [<c05f5cec>] (really_probe+0x1f0/0x458)
[   15.753338] [<c05f5cec>] (really_probe) from [<c05f61c4>] (driver_probe_device+0x70/0x1c4)
[   15.761584] [<c05f61c4>] (driver_probe_device) from [<c05f6580>] (device_driver_attach+0x58/0x60)
[   15.770439] [<c05f6580>] (device_driver_attach) from [<c05f6654>] (__driver_attach+0xcc/0x170)
[   15.779032] [<c05f6654>] (__driver_attach) from [<c05f40d8>] (bus_for_each_dev+0x58/0x7c)
[   15.787191] [<c05f40d8>] (bus_for_each_dev) from [<c05f4ffc>] (bus_add_driver+0xdc/0x1f8)
[   15.795352] [<c05f4ffc>] (bus_add_driver) from [<c05f6ed8>] (driver_register+0x7c/0x110)
[   15.803425] [<c05f6ed8>] (driver_register) from [<c01027bc>] (do_one_initcall+0x70/0x1b8)
[   15.811588] [<c01027bc>] (do_one_initcall) from [<c01a1094>] (do_init_module+0x58/0x1f8)
[   15.819660] [<c01a1094>] (do_init_module) from [<c01a0074>] (load_module+0x1e58/0x23c8)
[   15.827646] [<c01a0074>] (load_module) from [<c01a0860>] (sys_finit_module+0xa0/0xd4)
[   15.835459] [<c01a0860>] (sys_finit_module) from [<c01011e0>] (__sys_trace_return+0x0/0x20)

Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Fixes: 4e64350f42e2 ("rtc: add STM32 RTC driver")
Cc: stable@vger.kernel.org
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1623087421-19722-1-git-send-email-martin.fuzzey@flowbird.group
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14 16:55:44 +02:00
Francois Gervais
0296c9057a rtc: pcf85063: fallback to parent of_node
commit 03531606ef4cda25b629f500d1ffb6173b805c05 upstream.

The rtc device node is always NULL.

Since v5.12-rc1-dontuse/3c9ea42802a1fbf7ef29660ff8c6e526c58114f6 this
will lead to a NULL pointer dereference.

To fix this use the parent node which is the i2c client node as set by
devm_rtc_allocate_device().

Using the i2c client node seems to be what other similar drivers do
e.g. rtc-pcf8563.c.

Signed-off-by: Francois Gervais <fgervais@distech-controls.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210310211026.27299-1-fgervais@distech-controls.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26 12:06:57 +02:00
Nobuhiro Iwamatsu
494ade7aba rtc: ds1307: Fix wday settings for rx8130
[ Upstream commit 204756f016726a380bafe619438ed979088bd04a ]

rx8130 wday specifies the bit position, not BCD.

Fixes: ee0981be7704 ("rtc: ds1307: Add support for Epson RX8130CE")
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210420023917.1949066-1-nobuhiro1.iwamatsu@toshiba.co.jp
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:05 +02:00
Michael Walle
0f9d467ff1 rtc: fsl-ftm-alarm: add MODULE_TABLE()
[ Upstream commit 7fcb86185978661c9188397d474f90364745b8d9 ]

The module doesn't load automatically. Fix it by adding the missing
MODULE_TABLE().

Fixes: 7b0b551dbc1e ("rtc: fsl-ftm-alarm: add FTM alarm driver")
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210414084006.17933-1-michael@walle.cc
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19 10:13:03 +02:00
David Gow
378f670e08 rtc: zynqmp: depend on HAS_IOMEM
[ Upstream commit ddd0521549a975e6148732d6ca6b89ffa862c0e5 ]

The Xilinx zynqmp RTC driver makes use of IOMEM functions like
devm_platform_ioremap_resource(), which are only available if
CONFIG_HAS_IOMEM is defined.

This causes the driver not to be enable under make ARCH=um allyesconfig,
even though it won't build.

By adding a dependency on HAS_IOMEM, the driver will not be enabled on
architectures which don't support it.

Fixes: 09ef18bcd5ac ("rtc: use devm_platform_ioremap_resource() to simplify code")
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210127035146.1523286-1-davidgow@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:03 +01:00
Bartosz Golaszewski
31c9ba0c38 rtc: s5m: select REGMAP_I2C
[ Upstream commit 1f0cbda3b452b520c5f3794f8f0e410e8bc7386a ]

The rtc-s5m uses the I2C regmap but doesn't select it in Kconfig so
depending on the configuration the build may fail. Fix it.

Fixes: 959df7778bbd ("rtc: Enable compile testing for Maxim and Samsung drivers")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210114102219.23682-2-brgl@bgdev.pl
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:57 +01:00
Uwe Kleine-König
757cd94ac8 rtc: pcf2127: only use watchdog when explicitly available
commit 71ac13457d9d1007effde65b54818106b2c2b525 upstream.

Most boards using the pcf2127 chip (in my bubble) don't make use of the
watchdog functionality and the respective output is not connected. The
effect on such a board is that there is a watchdog device provided that
doesn't work.

So only register the watchdog if the device tree has a "reset-source"
property.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[RV: s/has-watchdog/reset-source/]
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201218101054.25416-3-rasmus.villemoes@prevas.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-09 13:46:22 +01:00
Uwe Kleine-König
acb821425c rtc: pcf2127: move watchdog initialisation to a separate function
commit 5d78533a0c53af9659227c803df944ba27cd56e0 upstream.

The obvious advantages are:

 - The linker can drop the watchdog functions if CONFIG_WATCHDOG is off.
 - All watchdog stuff grouped together with only a single function call
   left in generic code.
 - Watchdog register is only read when it is actually used.
 - Less #ifdefery

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200924105256.18162-2-u.kleine-koenig@pengutronix.de
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-09 13:46:22 +01:00
Zheng Liang
acc3c8cc27 rtc: pl031: fix resource leak in pl031_probe
[ Upstream commit 1eab0fea2514b269e384c117f5b5772b882761f0 ]

When devm_rtc_allocate_device is failed in pl031_probe, it should release
mem regions with device.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zheng Liang <zhengliang6@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201112093139.32566-1-zhengliang6@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:53 +01:00
Dinghao Liu
0ad9a6e613 rtc: sun6i: Fix memleak in sun6i_rtc_clk_init
[ Upstream commit 28d211919e422f58c1e6c900e5810eee4f1ce4c8 ]

When clk_hw_register_fixed_rate_with_accuracy() fails,
clk_data should be freed. It's the same for the subsequent
two error paths, but we should also unregister the already
registered clocks in them.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201020061226.6572-1-dinghao.liu@zju.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:53 +01:00
Nikita Shubin
783c5d48b2 rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time
commit 00c33482bb6110bce8110daa351f9b3baf4df7dc upstream.

Mismatch in probe platform_set_drvdata set's and method's that call
dev_get_platdata will result in "Unable to handle kernel NULL pointer
dereference", let's use according method for getting driver data after
platform_set_drvdata.

8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = (ptrval)
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.10-00003-g723e101e0037-dirty #4
Hardware name: Technologic Systems TS-72xx SBC
PC is at ep93xx_rtc_read_time+0xc/0x2c
LR is at __rtc_read_time+0x4c/0x8c
[...]
[<c02b01c8>] (ep93xx_rtc_read_time) from [<c02ac38c>] (__rtc_read_time+0x4c/0x8c)
[<c02ac38c>] (__rtc_read_time) from [<c02ac3f8>] (rtc_read_time+0x2c/0x4c)
[<c02ac3f8>] (rtc_read_time) from [<c02acc54>] (__rtc_read_alarm+0x28/0x358)
[<c02acc54>] (__rtc_read_alarm) from [<c02abd80>] (__rtc_register_device+0x124/0x2ec)
[<c02abd80>] (__rtc_register_device) from [<c02b028c>] (ep93xx_rtc_probe+0xa4/0xac)
[<c02b028c>] (ep93xx_rtc_probe) from [<c026424c>] (platform_drv_probe+0x24/0x5c)
[<c026424c>] (platform_drv_probe) from [<c0262918>] (really_probe+0x218/0x374)
[<c0262918>] (really_probe) from [<c0262da0>] (device_driver_attach+0x44/0x60)
[<c0262da0>] (device_driver_attach) from [<c0262e70>] (__driver_attach+0xb4/0xc0)
[<c0262e70>] (__driver_attach) from [<c0260d44>] (bus_for_each_dev+0x68/0xac)
[<c0260d44>] (bus_for_each_dev) from [<c026223c>] (driver_attach+0x18/0x24)
[<c026223c>] (driver_attach) from [<c0261dd8>] (bus_add_driver+0x150/0x1b4)
[<c0261dd8>] (bus_add_driver) from [<c026342c>] (driver_register+0xb0/0xf4)
[<c026342c>] (driver_register) from [<c0264210>] (__platform_driver_register+0x30/0x48)
[<c0264210>] (__platform_driver_register) from [<c04cb9ac>] (ep93xx_rtc_driver_init+0x10/0x1c)
[<c04cb9ac>] (ep93xx_rtc_driver_init) from [<c000973c>] (do_one_initcall+0x7c/0x1c0)
[<c000973c>] (do_one_initcall) from [<c04b9ecc>] (kernel_init_freeable+0x168/0x1ac)
[<c04b9ecc>] (kernel_init_freeable) from [<c03b2228>] (kernel_init+0x8/0xf4)
[<c03b2228>] (kernel_init) from [<c00082c0>] (ret_from_fork+0x14/0x34)
Exception stack(0xc441dfb0 to 0xc441dff8)
dfa0:                                     00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e12fff1e e92d4010 e590303c e1a02001 (e5933000)
---[ end trace c914d6030eaa95c8 ]---

Fixes: b809d192eb98 ("rtc: ep93xx: stop setting platform_data")
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201201095507.10317-1-nikita.shubin@maquefel.me
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:29 +01:00
Dan Carpenter
c647cc8e58 rtc: pcf2127: fix pcf2127_nvmem_read/write() returns
[ Upstream commit ba1c30bf3f2536f248d262c6f257b5a787305991 ]

These functions should return zero on success.  Non-zero returns are
treated as error.  On some paths, this doesn't matter but in
nvmem_cell_read() a non-zero return would be passed to ERR_PTR() and
lead to an Oops.

Fixes: d6c3029f32f7 ("rtc: pcf2127: add support for accessing internal static RAM")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201022070451.GA2817669@mwanda
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:52:57 +01:00
Linus Torvalds
b7769c45b8 RTC for 5.10
Subsystem:
  - new generic DT properties: aux-voltage-chargeable, trickle-voltage-millivolt
 
 New driver:
  - Microcrystal RV-3032
 
 Drivers:
  - ds1307: use aux-voltage-chargeable
  - r9701, rx8010: modernization of the driver
  - rv3028: fix clock output, trickle resistor values, RAM configuration
    registers
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Merge tag 'rtc-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "A new driver this cycle is making the bulk of the changes and the
  rx8010 driver has been rework to use the modern APIs.

  Summary:

  Subsystem:
   - new generic DT properties: aux-voltage-chargeable,
     trickle-voltage-millivolt

  New driver:
   - Microcrystal RV-3032

  Drivers:
   - ds1307: use aux-voltage-chargeable
   - r9701, rx8010: modernization of the driver
   - rv3028: fix clock output, trickle resistor values, RAM
     configuration registers"

* tag 'rtc-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (50 commits)
  rtc: r9701: set range
  rtc: r9701: convert to devm_rtc_allocate_device
  rtc: r9701: stop setting RWKCNT
  rtc: r9701: remove useless memset
  rtc: r9701: stop setting a default time
  rtc: r9701: remove leftover comment
  rtc: rv3032: Add a driver for Microcrystal RV-3032
  dt-bindings: rtc: rv3032: add RV-3032 bindings
  dt-bindings: rtc: add trickle-voltage-millivolt
  rtc: rv3028: ensure ram configuration registers are saved
  rtc: rv3028: factorize EERD bit handling
  rtc: rv3028: fix trickle resistor values
  rtc: rv3028: fix clock output support
  rtc: mt6397: Remove unused member dev
  rtc: rv8803: simplify the return expression of rv8803_nvram_write
  rtc: meson: simplify the return expression of meson_vrtc_probe
  rtc: rx8010: rename rx8010_init_client() to rx8010_init()
  rtc: ds1307: enable rx8130's backup battery, make it chargeable optionally
  rtc: ds1307: consider aux-voltage-chargeable
  rtc: ds1307: store previous charge default per chip
  ...
2020-10-21 11:22:08 -07:00
Alexandre Belloni
35331b506f rtc: r9701: set range
Set range and remove the set_time check. This is a classic BCD RTC.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-6-alexandre.belloni@bootlin.com
2020-10-19 22:48:55 +02:00
Alexandre Belloni
dfe13cf2ae rtc: r9701: convert to devm_rtc_allocate_device
This allows further improvement of the driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-5-alexandre.belloni@bootlin.com
2020-10-19 22:48:55 +02:00
Alexandre Belloni
8b34134907 rtc: r9701: stop setting RWKCNT
tm_wday is never checked for validity and it is not read back in
r9701_get_datetime. Avoid setting it to stop tripping static checkers:

        drivers/rtc/rtc-r9701.c:109 r9701_set_datetime()
        error: undefined (user controlled) shift '1 << dt->tm_wday'

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-4-alexandre.belloni@bootlin.com
2020-10-19 22:48:55 +02:00
Alexandre Belloni
2a8f3380c9 rtc: r9701: remove useless memset
The RTC core already sets to zero the struct rtc_tie it passes to the
driver, avoid doing it a second time.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-3-alexandre.belloni@bootlin.com
2020-10-19 22:48:55 +02:00
Alexandre Belloni
7390bec4ed rtc: r9701: stop setting a default time
It doesn't make sense to set the RTC to a default value at probe time. Let
the core handle invalid date and time.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-2-alexandre.belloni@bootlin.com
2020-10-19 22:48:55 +02:00