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omap8250_restore_regs() accesses UART_IER. This register is
modified twice by each console write (serial8250_console_write())
under the port lock. However, not all calls to omap8250_restore_regs()
are under the port lock.
Add the missing port locking around omap8250_restore_regs() calls. Add
lockdep notation to the omap8250_restore_regs().
Note that this is not fixing a real problem because the serial devices
are resumed before console printing is enabled.
However, adding this locking allows for clean locking semantics
for omap8250_restore_regs() so that lockdep can be used to identify
possible problems in the future. It also simplifies synchronization
of UART_IER in general by not needing to rely on such implementation
details.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-7-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The rx_dma() callback (omap_8250_rx_dma) accesses UART_IER. This
register is modified twice by each console write
(serial8250_console_write()) under the port lock. However, not
all calls to the rx_dma() callback are under the port lock.
Add the missing port locking around rx_dma() callback calls. Add
lockdep notation to the omap_8250_rx_dma().
Note that this is not fixing a real problem because:
1. Currently DMA is forced off for 8250_omap consoles.
2. The serial devices are resumed before console printing is enabled.
However, adding this locking allows for clean locking semantics
for the rx_dma() callback so that lockdep can be used to identify
possible problems in the future. It also simplifies synchronization
of UART_IER in general by not needing to rely on implementation
details such as 1 and 2.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-6-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The uarts_ops stop_rx() callback expects that the port->lock is
taken and interrupts are disabled.
Fixes: 1fe0e1fa3209 ("serial: 8250_omap: Handle optional overrun-throttle-ms property")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230525093159.223817-4-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_ops startup() callback is called without interrupts
disabled and without port->lock locked, relatively late during the
boot process (from the call path of console_on_rootfs()). If the
device is a console, it was already previously registered and could
be actively printing messages.
The console printing function serial8250_console_write() modifies
the interrupt register (UART_IER) under the port->lock with the
pattern: read, clear, restore.
Since some startup() callbacks are modifying UART_IER without the
port->lock locked, it is possible that the value intended to be
written by the startup() callback will get overwritten and be
lost.
CPU0 CPU1
serial8250_console_write omap_8250_startup
-------------------------- -----------------
spin_lock(port->lock)
oldval = read(UART_IER)
uart_console_write()
write(newval, UART_IER)
write(oldval, UART_IER)
spin_unlock(port->lock)
Add port->lock synchronization to the 8250 startup() callbacks
where they need to access UART_IER. This avoids racing with
serial8250_console_write().
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Smatch reports:
drivers/tty/serial/8250/8250_bcm7271.c:1120 brcmuart_probe() warn:
'baud_mux_clk' from clk_prepare_enable() not released on lines: 1032.
The issue is fixed by using a managed clock.
Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Reported-by: XuDong Liu <m202071377@hust.edu.cn>
Link: https://lore.kernel.org/lkml/20230424125100.4783-1-m202071377@hust.edu.cn/
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230427181916.2983697-3-opendmb@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sw_baud clock must be disabled when the device driver is not
connected to the device. This now occurs when probe fails and
upon remove.
Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Reported-by: XuDong Liu <m202071377@hust.edu.cn>
Link: https://lore.kernel.org/lkml/20230424125100.4783-1-m202071377@hust.edu.cn/
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230427181916.2983697-2-opendmb@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With W=1:
drivers/tty/serial/8250/8250_port.c:679: warning: Function parameter or member 'termios' not described in 'serial8250_em485_config'
Fix this by documenting the parameter.
Fixes: ae50bb2752836277 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/2bd1e62be1d5d33333002910372feecc6d52e78f.1682071013.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for Advantech PCI-1611U card
Advantech provides opensource drivers for this and many others card
based on legacy copy of 8250_pci driver called adv950
https://www.advantech.com/emt/support/details/driver?id=1-TDOIMJ
It is hard to maintain to run as out of tree module on newer kernels.
Just adding PCI ID to kernel 8250_pci works perfect.
Signed-off-by: Vitaliy Tomin <tomin@iszf.irk.ru>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20230423034512.2671157-1-tomin@iszf.irk.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Possibly the last PCI controller-based (i.e. not a soft/winmodem)
dial-up modem one can still buy.
Looks to have a stock XR17C154 PCI UART chip for communication, but for
some reason when provisioning the PCI IDs they swapped the vendor and
subvendor IDs. Otherwise this card would have worked out of the box.
Searching online, some folks seem to not have this issue and others do,
so it is possible only some batches of cards have this error.
Create a new macro to handle the switched IDs and add support here.
Signed-off-by: Andrew Davis <afd@ti.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230420160209.28221-1-afd@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As unmapped registers are at the tail of the array, the ARRAY_SIZE()
condition will catch them just fine. No need to define special
value for them.
Convert the arrays to u8 as all entiries are now positive.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230511121029.13128-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A non-trivial amount of RT288x/Au1xxx code is encapsulated into
ifdeffery in 8250_port / 8250_early and some if UPIO_AU blocks.
Create a separate file from them.
Also handle errors properly in the cases where RT288x/Au1xxx code is
not configured.
It seems that 0x1000 mapsize is likely overkill but I've kept it the
same as previously (the value was shrunk to that value in commit
b2b13cdfd05e ("SERIAL 8250: Fixes for Alchemy UARTs.")). Seemingly, the
driver only needs to access register at 0x28 for the divisor latch.
The Kconfig side is a bit tricky. As SERIAL_8250_RT288X is bool it can
only be =y. It is possible to have SERIAL_8250=m + SERIAL_8250_RT288X=y
which required altering when 8250/ is included or the rt288x would not
be built.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230511121029.13128-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add mapsize, bugs, and divisor latch read/write functions
(->dl_read/write()) into plat_serial8250_port to carry the setup
necessary for RT288x/Au1xxx devices over to uart port.
Document the added members with kerneldoc style but do not enable
kerneldoc yet as there are many fields which remain undocumented.
While at it, convert .bugs in struct uart_8250_port to u16 to match it
with the type used in struct plat_serial8250_port.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230511121029.13128-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Divisor latch read/write functions currently handle the value is int.
As the value is related to HW context, u32 makes much more sense than a
signed type.
While at it, name the parameters in the callback signature.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230511121029.13128-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We already allocate CONFIG_SERIAL_8250_NR_UARTS, but only allow using
CONFIG_SERIAL_8250_RUNTIME_UARTS uarts unless nr_uarts module params
is set. This causes issues for using distro kernels on SoCs with a
large number of serial ports.
Let's allow up to CONFIG_SERIAL_8250_NR_UARTS instead. To do this, we init
the ports as needed if the initial uarts was too low. This way there's no
need to set the value for CONFIG_SERIAL_8250_RUNTIME_UARTS to some SoC
specific higher value. Typically the default value of 4 can be used as
set for legacy reasons.
Note that limiting the number of intial uarts still works as before
unless a serial console on a higher port is specified. In this case we
will increase the nr_ports up to the console port specified.
Suggested-by: Andrew Davis <afd@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508111903.39339-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When unbinding the console uart, we want to power down the uart hardware
on remove. For the console uart, the normal shutdown path will never get
called as the cons_filp stays open. Let's rearrange the dma related
functions a bit so we can call driver shutdown also on console uart rebind.
Currently we set up->dma on probe, but that causes issues calling
omap_8250_shutdown() on remove. The dma startup will not get called on
the next rebind as we still have up->dma set from probe.
Note that serial8250_release_dma() already checks for dma so we can
remove the check for it in 8205_omap driver.
With these changes we also avoid hogging dma virtual channels for the
unused uarts that may be limited on some devices.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-5-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We have the struct uart_8250_port instance recycled on device rebind while
the struct omap8250_priv instance is not. For the console uart,
__tty_hangup() does not call tty->ops->hangup() as cons_filp stays open,
and uart shutdown won't get called. This means we have a stale
priv->wakeirq handler around after unbind, and port->irq is not freed on
unbind.
There's no need to claim the interrupts on startup. We can fix this and
simplify the driver a bit by claiming the interrupts in probe, and clearing
them on remove. For the device interrupt, we can use devm_request_irq().
To do this, we change omap8250_irq() to use struct omap8250_priv data
directly so we don't have to wait for the assigned port from
serial8250_register_8250_port().
We must also drop IRQF_SHARED to set IRQ_NOAUTOEN to avoid spurious
interrupts until the port has been registered. There's no need for
IRQF_SHARED for 8250_omap, the serial port interrupt lines are dedicated
lines.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-4-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We must idle the uart only after serial8250_unregister_port(). Otherwise
unbinding the uart via sysfs while doing cat on the port produces an
imprecise external abort:
mem_serial_in from omap_8250_pm+0x44/0xf4
omap_8250_pm from uart_hangup+0xe0/0x194
uart_hangup from __tty_hangup.part.0+0x37c/0x3a8
__tty_hangup.part.0 from uart_remove_one_port+0x9c/0x22c
uart_remove_one_port from serial8250_unregister_port+0x60/0xe8
serial8250_unregister_port from omap8250_remove+0x6c/0xd0
omap8250_remove from platform_remove+0x28/0x54
Turns out the driver needs to have runtime PM functional before the
driver probe calls serial8250_register_8250_port(). And it needs
runtime PM after driver remove calls serial8250_unregister_port().
On probe, we need to read registers before registering the port in
omap_serial_fill_features_erratas(). We do that with custom uart_read()
already.
On remove, after serial8250_unregister_port(), we need to write to the
uart registers to idle the device. Let's add a custom uart_write() for
that.
Currently the uart register access depends on port->membase to be
initialized, which won't work after serial8250_unregister_port().
Let's use priv->membase instead, and use it for runtime PM related
functions to remove the dependency to port->membase for early and
late register access.
Note that during use, we need to check for a valid port in the runtime PM
related functions. This is needed for the optional wakeup configuration.
We now need to set the drvdata a bit earlier so it's available for the
runtime PM functions.
With the port checks in runtime PM functions, the old checks for priv in
omap8250_runtime_suspend() and omap8250_runtime_resume() functions are no
longer needed and are removed.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-3-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If serial8250_register_8250_port() fails, the SoC can hang as the
deferred PMQoS work will still run as is not flushed and removed.
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230508082014.23083-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of tty/serial driver updates for 6.4-rc1.
Nothing major, just lots of tiny, constant, forward development. This
includes:
- obligatory n_gsm updates and feature additions
- 8250_em driver updates
- sh-sci driver updates
- dts cleanups and updates
- general cleanups and improvements by Ilpo and Jiri
- other small serial driver core fixes and driver updates
All of these have been in linux-next for a while with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial updates from Greg KH:
"Here is the big set of tty/serial driver updates for 6.4-rc1.
Nothing major, just lots of tiny, constant, forward development. This
includes:
- obligatory n_gsm updates and feature additions
- 8250_em driver updates
- sh-sci driver updates
- dts cleanups and updates
- general cleanups and improvements by Ilpo and Jiri
- other small serial driver core fixes and driver updates
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (87 commits)
n_gsm: Use array_index_nospec() with index that comes from userspace
tty: vt: drop checks for undefined VT_SINGLE_DRIVER
tty: vt: distribute EXPORT_SYMBOL()
tty: vt: simplify some cases in tioclinux()
tty: vt: reformat tioclinux()
tty: serial: sh-sci: Fix end of transmission on SCI
tty: serial: sh-sci: Add support for tx end interrupt handling
tty: serial: sh-sci: Fix TE setting on SCI IP
tty: serial: sh-sci: Add RZ/G2L SCIFA DMA rx support
tty: serial: sh-sci: Add RZ/G2L SCIFA DMA tx support
serial: max310x: fix IO data corruption in batched operations
serial: core: Disable uart_start() on uart_remove_one_port()
serial: 8250: Reinit port->pm on port specific driver unbind
serial: 8250: Add missing wakeup event reporting
tty: serial: fsl_lpuart: use UARTMODIR register bits for lpuart32 platform
tty: serial: fsl_lpuart: adjust buffer length to the intended size
serial: fix TIOCSRS485 locking
serial: make SiFive serial drivers depend on ARCH_ symbols
tty: synclink_gt: don't allocate and pass dummy flags
tty: serial: simplify qcom_geni_serial_send_chunk_fifo()
...
Merge ACPI bus type driver changes, ACPI backlight driver updates and a
series of cleanups related to of.h for 6.4-rc1:
- Ensure that ACPI notify handlers are not running after removal and
clean up code in acpi_sb_notify() (Rafael Wysocki).
- Remove register_backlight_delay module option and code and remove
quirks for false-positive backlight control support advertised on
desktop boards (Hans de Goede).
- Replace irqdomain.h include with struct declarations in ACPI headers
and update several pieces of code previously including of.h
implicitly through those headers (Rob Herring).
* acpi-bus:
ACPI: bus: Ensure that notify handlers are not running after removal
ACPI: bus: Add missing braces to acpi_sb_notify()
* acpi-video:
ACPI: video: Remove desktops without backlight DMI quirks
ACPI: video: Remove register_backlight_delay module option and code
* acpi-misc:
ACPI: Replace irqdomain.h include with struct declarations
fpga: lattice-sysconfig-spi: Add explicit include for of.h
tpm: atmel: Add explicit include for of.h
virtio-mmio: Add explicit include for of.h
pata: ixp4xx: Add explicit include for of.h
ata: pata_macio: Add explicit include of irqdomain.h
serial: 8250_tegra: Add explicit include for of.h
net: rfkill-gpio: Add explicit include for of.h
staging: iio: resolver: ad2s1210: Add explicit include for of.h
iio: adc: ad7292: Add explicit include for of.h
When we unbind a serial port hardware specific 8250 driver, the generic
serial8250 driver takes over the port. After that we see an oops about 10
seconds later. This can produce the following at least on some TI SoCs:
Unhandled fault: imprecise external abort (0x1406)
Internal error: : 1406 [#1] SMP ARM
Turns out that we may still have the serial port hardware specific driver
port->pm in use, and serial8250_pm() tries to call it after the port
specific driver is gone:
serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base]
uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base]
uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c
__tty_hangup.part.0 from disassociate_ctty+0x154/0x20c
disassociate_ctty from do_exit+0x744/0xaac
do_exit from do_group_exit+0x40/0x8c
do_group_exit from __wake_up_parent+0x0/0x1c
Let's fix the issue by calling serial8250_set_defaults() in
serial8250_unregister_port(). This will set the port back to using
the serial8250 default functions, and sets the port->pm to point to
serial8250_pm.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230418101407.12403-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An 8250 UART configured as a wake-up source would not have reported
itself through sysfs as being the source of wake-up, correct that.
Fixes: b3b708fa2780 ("wake up from a serial port")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230414170241.2016255-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With linux/acpi.h no longer implicitly including of.h, add an explicit
include of of.h to fix the following error:
drivers/tty/serial/8250/8250_tegra.c:68:15: error: implicit declaration of function 'of_alias_get_id' [-Werror=implicit-function-declaration]
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Hans de Goede reported Bluetooth adapters (HCIs) connected over an UART
connection failed due corrupted Rx payload. The problem was narrowed
down to DMA Rx starting on UART_IIR_THRI interrupt. The problem occurs
despite LSR having DR bit set, which is precondition for attempting to
start DMA Rx in the first place.
From a debug patch:
[x.807834] 8250irq: iir=cc lsr+saved=60 received=0/15 ier=0f dma_t/rx/err=0/0/0
[x.808676] 8250irq: iir=c2 lsr+saved=61 received=0/0 ier=0f dma_t/rx/err=0/0/0
[x.808776] 8250irq: iir=cc lsr+saved=60 received=1/12 ier=0d dma_t/rx/err=0/1/0
[x.808870] Bluetooth: hci0: Frame reassembly failed (-84)
In the debug snippet, received field indicates 1 byte was transferred
over DMA and 12 bytes after that with the non-DMA Rx. The sole byte DMA
handled was corrupted (gets zeroed) which leads to the HCI failure.
This problem became apparent after commit e8ffbb71f783 ("serial: 8250:
use THRE & __stop_tx also with DMA") changed Tx stop behavior. Tx stop
is now triggered from a THRI interrupt.
Despite that this problem looks like a HW bug, this fix is not adding
UART_BUG_xx flag to the driver beucase it seems useful in general to
avoid starting DMA when there are only a few bytes to transfer.
Skipping DMA for small transfers avoids the extra overhead DMA incurs.
Thus, don't setup DMA Rx on UART_IIR_THRI but leave it to a subsequent
interrupt which has Rx a related IIR value.
By returning false from handle_rx_dma(), the DMA vs non-DMA decision is
postponed until either UART_IIR_RDI (FIFO threshold worth of bytes
awaiting) or UART_IIR_TIMEOUT (inter-character timeout) triggers at a
later time which allows better to discern whether the number of bytes
warrants starting DMA or not.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e8ffbb71f783 ("serial: 8250: use THRE & __stop_tx also with DMA")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230317103034.12881-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's a potential race before THRE/TEMT deasserts when DMA Tx is
starting up (or the next batch of continuous Tx is being submitted).
This can lead to misdetecting Tx empty condition.
It is entirely normal for THRE/TEMT to be set for some time after the
DMA Tx had been setup in serial8250_tx_dma(). As Tx side is definitely
not empty at that point, it seems incorrect for serial8250_tx_empty()
claim Tx is empty.
Fix the race by also checking in serial8250_tx_empty() whether there's
DMA Tx active.
Note: This fix only addresses in-kernel race mainly to make using
TCSADRAIN/FLUSH robust. Userspace can still cause other races but they
seem userspace concurrency control problems.
Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230317113318.31327-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need the tty/serial fixes in here and it resolves a merge conflict
with:
drivers/tty/serial/8250/8250_em.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The arbitration of the UART DMA is mishandled for a few
exceptional cases when probing and releasing the driver.
It is possible that the DMA register spaces are not defined in
device tree for an instance of the driver, so attempts to access
the registers in brcmuart_arbitration() would use NULL pointers.
It is also possible for the probe function to return an error
while still holding the UART DMA. This would prevent the UART
DMA from being claimed by an instance that could use it.
These errors are addressed by only releasing the UART DMA if it
is held by this instance (i.e. priv->dma_enabled == 1) and
directing early error paths in probe to this common release_dma
handling.
Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230309190224.687380-1-opendmb@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As per RZ/V2M hardware manual(Rev.1.30 Jun, 2022), UART IP has a
restriction as mentioned below.
40.6.1 Point for Caution when Changing the Register Settings:
When changing the settings of the following registers, a PRESETn master
reset or FIFO reset + SW reset (FCR[2],FCR[1], HCR0[7]) must be input to
re-initialize them.
Target Registers: FCR, LCR, MCR, DLL, DLM, HCR0.
Add serial8250_em_reg_update() and serial8250_em_serial_out_helper() to
handle this restriction. serial8250_em_serial_out_helper() is identical to
previous serial8250_em_serial_out() except that UART_FCR macro is removed
from serial8250_em_serial_out_helper() as it is now handled by serial8250_
em_serial_out().
DLL/DLM register can be updated only by setting LCR[7]. So the
updation of LCR[7] will perform reset for DLL/DLM register changes.
EMMA mobile has the same register set as RZ/V2M and this patch is tested on
EMEV2 board. So, there is no harm in applying the same restriction here as
well as the HW manual for EMMA mobile is not updated for a long time.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-8-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART_FCR shares the same offset with UART_IIR. We cannot use UART_FCR
in serial8250_em_serial_in() as it overlaps with UART_IIR.
Define UART_FCR_EM macro with a high value to avoid overlapping
with existing UART_* register defines and define another macro
UART_FCR_EM_HW for the real offset.
Use these macros in serial8250_em_serial{_in/_out} function to
read/write FCR register.
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-7-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify clk handling in probe() by replacing devm_clk_get()->devm_
clk_get_enabled(). This replaces the usage of clk_prepare_enable/clk_
disable_unprepare() in probe()/remove(). After that sclk is no
longer required in struct serial8250_em_priv and is replaced by a
local variable sclk in probe().
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-6-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify probe() by using dev_err_probe() instead of dev_err() and
add a local variable 'dev' to replace '&pdev->dev'.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As per HW manual for EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.
Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart
support") made the SERIAL_8250_PCI1XXXX driver enabled when SERIAL_8250
is enabled, disable it as this driver does not need to be enabled by
default
Fixes: 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/lkml/CAHk-=whhFCeeuo6vTEmNSx6S-KKkugxgzN_W5Z6v-9yH9gc3Zw@mail.gmail.com/
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230305145124.13444-1-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 8250 handle_irq callback is not just called from the interrupt
handler but also from a timer callback when polling (e.g. for ports
without an interrupt line). Consequently the callback must explicitly
disable interrupts to avoid a potential deadlock with another interrupt
in polled mode.
Fix up the two paths in the freescale callback that failed to re-enable
interrupts when polling.
Fixes: 853a9ae29e97 ("serial: 8250: fix handle_irq locking")
Cc: stable@vger.kernel.org # 5.13
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As per HW manual for EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.
Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
REGMAP is a hidden (not user visible) symbol. Users cannot set it
directly thru "make *config", so drivers should select it instead of
depending on it if they need it.
Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.
Therefore, change the use of "depends on REGMAP" to "select REGMAP".
Fixes: 8d310c9107a2 ("drivers/tty/serial/8250: Make Aspeed VUART SIRQ polarity configurable")
Cc: stable <stable@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oskar Senft <osk@google.com>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20230226053953.4681-9-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pci1xxxx's quad-uart function has the capability to wake up UART
from suspend state. Enable wakeup before entering into suspend and
disable wakeup on resume.
Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pci1xxxx uart supports RS485 mode of operation in the hardware with
auto-direction control with configurable delay for releasing RTS after
the transmission. This patch adds support for the RS485 mode.
Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-4-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pci1xxxx is a PCIe switch with a multi-function endpoint on one of
its downstream ports. Quad-uart is one of the functions in the
multi-function endpoint. This driver loads for the quad-uart and
enumerates single or multiple instances of uart based on the PCIe
subsystem device ID.
Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-3-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The relevant history introducing serial_lsr_in() looks as follows:
$ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
* df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
|\
| * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
* | ...
* | bdb70c424df1 serial: 8250: Create serial_lsr_in()
* | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
* | ...
|/
o 9fafe733514b tty: remove CMSPAR ifdefs
So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
introduced twice and in one branch it was followed up by commit
bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
explicit lsr_saved_flags handling into a new function serial_lsr_in().
When the two branches were merged in commit df36f3e3fbb7, we got both,
serial_lsr_in() and the explicit lsr_saved_flags handling.
So drop the explicit lsr_saved_flags handling.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230202104501.264686-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As DMA Rx can be completed from two places, it is possible that DMA Rx
completes before DMA completion callback had a chance to complete it.
Once the previous DMA Rx has been completed, a new one can be started
on the next UART interrupt. The following race is possible
(uart_unlock_and_check_sysrq_irqrestore() replaced with
spin_unlock_irqrestore() for simplicity/clarity):
CPU0 CPU1
dma_rx_complete()
serial8250_handle_irq()
spin_lock_irqsave(&port->lock)
handle_rx_dma()
serial8250_rx_dma_flush()
__dma_rx_complete()
dma->rx_running = 0
// Complete DMA Rx
spin_unlock_irqrestore(&port->lock)
serial8250_handle_irq()
spin_lock_irqsave(&port->lock)
handle_rx_dma()
serial8250_rx_dma()
dma->rx_running = 1
// Setup a new DMA Rx
spin_unlock_irqrestore(&port->lock)
spin_lock_irqsave(&port->lock)
// sees dma->rx_running = 1
__dma_rx_complete()
dma->rx_running = 0
// Incorrectly complete
// running DMA Rx
This race seems somewhat theoretical to occur for real but handle it
correctly regardless. Check what is the DMA status before complething
anything in __dma_rx_complete().
Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__dma_rx_complete() is called from two places:
- Through the DMA completion callback dma_rx_complete()
- From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT
The former does not hold port's lock during __dma_rx_complete() which
allows these two to race and potentially insert the same data twice.
Extend port's lock coverage in dma_rx_complete() to prevent the race
and check if the DMA Rx is still pending completion before calling
into __dma_rx_complete().
Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
