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None of the fields is ever set by board code, and both of them are set
in the driver at probe time. Move them out of struct plat_sci_port to
struct sci_port.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Memory and IRQ resources are currently passed to the driver through
platform data. Support passing them through the standard platform
resources mechanism instead. This deprecates platform data resources.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The IRQ number can't be modified by the user as the port is fixed.
There's no need to check the new IRQ number as it will be ignored by the
core.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The base address, IRQ and baud rate generator parent clock rate can't be
changed by userspace. Mark the port as fixed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The driver checks if the interrupt number is greater than nr_irqs and
returns an error in that case. The same check is already performed by
the caller, remove it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Rewrite the baud rate register value calculations in easier to read
forms. The computed value isn't modified.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
there is an overflow in the code :
cyz_polling_cycle = (arg * HZ) / 1000,
the multiplicator arg comes from user, so it may be an overflow if
arg is a big number. And the value of cyc_polling_cycle will be
wrong when it is used next time.
Reported-by: Qixue Xiao <xiaoqixue_1@163.com>
Suggested-by: Yongjian Xu <xuyongjiande@gmail.com>
Suggested-by: Yu Chen <chyyuu@gmail.com>
Signed-off-by: Qixue Xiao <xiaoqixue_1@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
New driver for NXP (Philips) UART ICs was introduced in September 2012.
Old driver no longer used anywhere, this patch removes it.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the initialisation of older Quatech serial cards which are fitted with
the AMCC PCI Matchmaker interface chip.
Signed-off-by: Jonathan Woithe (jwoithe@just42.net)
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 'tty: xuartps: Implement BREAK detection, add SYSRQ support'
(0c0c47bc40a2e358d593b2d7fb93b50027fbfc0c) introduced sysrq support
without properly guarding sysrq specific code which results in build
errors when sysrq is disabled:
DNAME=KBUILD_STR(xilinx_uartps)" -c -o
drivers/tty/serial/.tmp_xilinx_uartps.o
drivers/tty/serial/xilinx_uartps.c
drivers/tty/serial/xilinx_uartps.c: In function 'xuartps_isr':
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
make[3]: *** [drivers/tty/serial/xilinx_uartps.o] Error 1
Reported-by: Masanari Iida <standby24x7@gmail.com>
Cc: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With block processing of echoed output, observed output order is still
required. Push completed echoes and echo commands prior to output.
Introduce echo_mark echo buffer index, which tracks completed echo
commands; ie., those submitted via commit_echoes but which may not
have been committed. Ensure that completed echoes are output prior
to subsequent terminal writes in process_echoes().
Fixes newline/prompt output order in cooked mode shell.
Cc: <stable@vger.kernel.org> # 3.12.x : 39434ab n_tty: Fix missing newline echo
Reported-by: Karl Dahlke <eklhad@comcast.net>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Karl Dahlke <eklhad@comcast.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer Intel PCHs with LPSS have the same Designware controllers than
Haswell but ACPI IDs are different. Add these IDs to the driver list.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mark the function hvc_poll_init() as static in hvc/hvc_console.c because
it is not used outside this file.
This eliminates the following warning in hvc/hvc_console.c:
drivers/tty/hvc/hvc_console.c:791:5: warning: no previous prototype for ‘hvc_poll_init’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Marks the functions gsm_cleanup_mux(), gsm_activate_mux(),
gsm_free_mux(), gsm_alloc_mux() and gsm_change_mtu() as static in
n_gsm.c because they are not used outside this file.
Also, drop the EXPORT_SYMBOL_GPL for the above mentioned functions
because nothing else in the kernel calls them.
This eliminates the following warnings in n_gsm.c:
drivers/tty/n_gsm.c:2022:6: warning: no previous prototype for ‘gsm_cleanup_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2076:5: warning: no previous prototype for ‘gsm_activate_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2120:6: warning: no previous prototype for ‘gsm_free_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2156:17: warning: no previous prototype for ‘gsm_alloc_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2714:5: warning: no previous prototype for ‘gsm_change_mtu’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When falling back from DMA to interrupt mode the receive interrupt has to
be re-enabled to catch new incoming data.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In pl011_rx_chars() if pl011_dma_rx_trigger_dma() succeeds it will disable
the receive interrupt, no need to do this again.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During initialisation, a UART may already be in use for a console, so
take care to preserve things like baud rate and data format to avoid
corrupting console output.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code to cope with a split tx/rx LCR_H register is non-trivial
so put it into it's own function to avoid duplication.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the pl011 is being used for a console, pl011_console_write forces
the control register (CR) to enable the UART for transmission and then
restores this to the original value afterwards. It does this while
holding the port lock.
Unfortunately, when the uart is started or shutdown - say in response to
userland using the serial device for a terminal - then this updates the
control register without any locking.
This means we can have
pl011_console_write Save CR
pl011_startup Initialise CR, e.g. enable receive
pl011_console_write Restore old CR with receive not enabled
this result is a serial port which doesn't respond to any input.
A similar race in reverse could happen when the device is shutdown.
We can fix these problems by taking the port lock when updating CR.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 17438217a6f5e33d920ed3821a4b857311cc2872 on request
of Linus Walleij:
Greg can you please drop or revert
commit 17438217a6f5e33d920ed3821a4b857311cc2872
"serial: pl011: use DMA RX polling by default"
from the TTY tree until this has been sorted out?
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
readline() inadvertently triggers an error recovery path when
pastes larger than 4k overrun the line discipline buffer. The
error recovery path discards input when the line discipline buffer
is full and operating in canonical mode and no newline has been
received. Because readline() changes the termios to non-canonical
mode to read the line char-by-char, the line discipline buffer
can become full, and then when readline() restores termios back
to canonical mode for the caller, the now-full line discipline
buffer triggers the error recovery.
When changing termios from non-canon to canon mode and the read
buffer contains data, simulate an EOF push _without_ the
DISABLED_CHAR in the read buffer.
Importantly for the readline() problem, the termios can be
changed back to non-canonical mode without changes to the read
buffer occurring; ie., as if the previous termios change had not
happened (as long as no intervening read took place).
Preserve existing userspace behavior which allows '\0's already
received in non-canon mode to be read as '\0's in canon mode
(rather than trigger add'l EOF pushes or an actual EOF).
Patch based on original proposal and discussion here
https://bugzilla.kernel.org/show_bug.cgi?id=55991
by Stas Sergeev <stsp@users.sourceforge.net>
Reported-by: Margarita Manterola <margamanterola@gmail.com>
Cc: Maximiliano Curia <maxy@gnuservers.com.ar>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Acked-by: Stas Sergeev <stsp@users.sourceforge.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a complex patch for refactoring CLPS711X serial driver.
Major changes:
- Eliminate <mach/hardware.h> usage.
- Devicetree support.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c49436b657d0 (serial: 8250_dw: Improve unwritable LCR workaround)
caused a regression. It added a check that the LCR was written properly
to detect and workaround the busy quirk, but the behaviour of bit 5
(UART_LCR_SPAR) differs between IP versions 3.00a and 3.14c per the
docs. On older versions this caused the check to fail and it would
repeatedly force idle and rewrite the LCR register, causing delays and
preventing any input from serial being received.
This is fixed by masking out UART_LCR_SPAR before making the comparison.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Tim Kryger <tim.kryger@linaro.org>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: Matt Porter <matt.porter@linaro.org>
Cc: Markus Mayer <markus.mayer@linaro.org>
Tested-by: Tim Kryger <tim.kryger@linaro.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a controlling tty is being hung up and the hang up is
waiting for a just-signalled tty reader or writer to exit, and a new tty
reader/writer tries to acquire an ldisc reference concurrently with the
ldisc reference release from the signalled reader/writer, the hangup
can hang. The new reader/writer is sleeping in ldsem_down_read() and the
hangup is sleeping in ldsem_down_write() [1].
The new reader/writer fails to wakeup the waiting hangup because the
wrong lock count value is checked (the old lock count rather than the new
lock count) to see if the lock is unowned.
Change helper function to return the new lock count if the cmpxchg was
successful; document this behavior.
[1] edited dmesg log from reporter
SysRq : Show Blocked State
task PC stack pid father
systemd D ffff88040c4f0000 0 1 0 0x00000000
ffff88040c49fbe0 0000000000000046 ffff88040c4a0000 ffff88040c49ffd8
00000000001d3980 00000000001d3980 ffff88040c4a0000 ffff88040593d840
ffff88040c49fb40 ffffffff810a4cc0 0000000000000006 0000000000000023
Call Trace:
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817a6649>] schedule+0x24/0x5e
[<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26
[<ffffffff817aa10c>] down_read_failed+0xe3/0x1b9
[<ffffffff817aa26d>] ldsem_down_read+0x8b/0xa5
[<ffffffff8142b5ca>] ? tty_ldisc_ref_wait+0x1b/0x44
[<ffffffff8142b5ca>] tty_ldisc_ref_wait+0x1b/0x44
[<ffffffff81423f5b>] tty_write+0x7d/0x28a
[<ffffffff814241f5>] redirected_tty_write+0x8d/0x98
[<ffffffff81424168>] ? tty_write+0x28a/0x28a
[<ffffffff8115d03f>] do_loop_readv_writev+0x56/0x79
[<ffffffff8115e604>] do_readv_writev+0x1b0/0x1ff
[<ffffffff8116ea0b>] ? do_vfs_ioctl+0x32a/0x489
[<ffffffff81167d9d>] ? final_putname+0x1d/0x3a
[<ffffffff8115e6c7>] vfs_writev+0x2e/0x49
[<ffffffff8115e7d3>] SyS_writev+0x47/0xaa
[<ffffffff817ab822>] system_call_fastpath+0x16/0x1b
bash D ffffffff81c104c0 0 5469 5302 0x00000082
ffff8800cf817ac0 0000000000000046 ffff8804086b22a0 ffff8800cf817fd8
00000000001d3980 00000000001d3980 ffff8804086b22a0 ffff8800cf817a48
000000000000b9a0 ffff8800cf817a78 ffffffff81004675 ffff8800cf817a44
Call Trace:
[<ffffffff81004675>] ? dump_trace+0x165/0x29c
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff8100edda>] ? save_stack_trace+0x26/0x41
[<ffffffff817a6649>] schedule+0x24/0x5e
[<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817a9f03>] ? down_write_failed+0xa3/0x1c9
[<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26
[<ffffffff817a9f0b>] down_write_failed+0xab/0x1c9
[<ffffffff817aa300>] ldsem_down_write+0x79/0xb1
[<ffffffff817aada3>] ? tty_ldisc_lock_pair_timeout+0xa5/0xd9
[<ffffffff817aada3>] tty_ldisc_lock_pair_timeout+0xa5/0xd9
[<ffffffff8142bf33>] tty_ldisc_hangup+0xc4/0x218
[<ffffffff81423ab3>] __tty_hangup+0x2e2/0x3ed
[<ffffffff81424a76>] disassociate_ctty+0x63/0x226
[<ffffffff81078aa7>] do_exit+0x79f/0xa11
[<ffffffff81086bdb>] ? get_signal_to_deliver+0x206/0x62f
[<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e
[<ffffffff81079b05>] do_group_exit+0x47/0xb5
[<ffffffff81086c16>] get_signal_to_deliver+0x241/0x62f
[<ffffffff810020a7>] do_signal+0x43/0x59d
[<ffffffff810f2af7>] ? __audit_syscall_exit+0x21a/0x2a8
[<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e
[<ffffffff81002655>] do_notify_resume+0x54/0x6c
[<ffffffff817abaf8>] int_signal+0x12/0x17
Reported-by: Sami Farin <sami.farin@gmail.com>
Cc: <stable@vger.kernel.org> # 3.12.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Turn clk_enable() and clk_disable() calls into clk_prepare_enable() and
clk_disable_unprepare() to get ready for the migration to the common
clock framework.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The break timer accesses hardware registers and thus requires the port
to be enabled. It currently ensures this by enabling the port at the
beginning of the timer handler, and disabling it at the end. However,
the enable/disable operations call the runtime PM sync functions, which
are not allowed in atomic context. The current situation is thus broken.
This change relies on non-atomic code to enable/disable the port. The
break timer will only be started from the IRQ handler, which already
runs with the port enabled. We just need to ensure that the port won't
be disabled with the timer running, and that's easily done by just
cancelling the timer in the port disable function.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Use the %zu and %pad printk specifiers to print size_t and dma_addr_t
variables, and cast pointers to uintptr_t instead of unsigned int where
applicable. This fixes warnings on platforms where pointers and/or
dma_addr_t have a different size than int.
Cc: linux-serial@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
By using dma_request_slave_channel_or_err(), the DMA slave ID can be
looked up from standard DT properties, and squirrelled away during
channel allocation. Hence, there's no need to use a custom DT property
to store the slave ID.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>
tty flip buffers use GFP_ATOMIC allocations for received data
which is to be processed by the line discipline. For each byte
received, an extra byte is used to indicate the error status of
that byte.
Instead, if the received data is error-free, encode the entire
buffer without status bytes.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 'tty: xuartps: Implement BREAK detection, add SYSRQ support'
(0c0c47bc40a2e358d593b2d7fb93b50027fbfc0c) introduced sysrq support
without properly guarding sysrq specific code which results in build
errors when sysrq is disabled:
DNAME=KBUILD_STR(xilinx_uartps)" -c -o
drivers/tty/serial/.tmp_xilinx_uartps.o
drivers/tty/serial/xilinx_uartps.c
drivers/tty/serial/xilinx_uartps.c: In function 'xuartps_isr':
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
make[3]: *** [drivers/tty/serial/xilinx_uartps.o] Error 1
Reported-by: Masanari Iida <standby24x7@gmail.com>
Cc: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the initialisation of older Quatech serial cards which are fitted with
the AMCC PCI Matchmaker interface chip.
Signed-off-by: Jonathan Woithe (jwoithe@just42.net)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We use "fw" in the next line after we release it. I've shifted the call
to release_firmware() down a couple lines to fix this.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer Intel PCHs with LPSS have the same Designware controllers than
Haswell but ACPI IDs are different. Add these IDs to the driver list.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
if the DMA driver isn't loaded "on time" then we crash in the irq handler:
| pch_uart 0000:02:0a.4: pch_request_dma:dma_request_channel FAILS(Tx)
| BUG: unable to handle kernel NULL pointer dereference at (null)
| IP: [<c0676ed9>] pch_uart_interrupt+0x739/0x940
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 60e93575476f (serial: samsung: enable clock before clearing pending
interrupts during init) added handling of the controller clock during init.
On most systems this clock is also one of the baud_clock sources and
possibly used by the earlycon and thus already enabled by the bootloader.
Therefore a gap exists between s3c24xx_serial_init_port disabling the
clock and an attached console reenabling it, making the transition from
earlycon to regular console possibly hang the system - as seen on my
S3C2442 based Freerunner today.
Therefore move the disabling of the clock from s3c24xx_serial_init_port
below the uart port registration, effectively creating an overlap and
keeping the clock running non-stop if the console wants to grab this port.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d7a68be4f265be10e24be931c257af30ca55566b,
'tty: Only perform flip buffer flush from tty_buffer_flush()',
removed buffer flushing from flush_to_ldisc().
Fix function header comment which describes the former behavior.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up
the PM callbacks.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is not preferred.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Making DMA RX polling optional when DMA is on was just
over-cautious: there is one single system in the kernel tree
using this facility, Ux500 and after some testing I turned
this on also for Ux500, which means it should simply be on
by default if DMA is enabled.
Cc: Jongsung Kim <neidhard.kim@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up
the PM callbacks.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ttyA has ld associated to n_gsm, when ttyA is closing, it triggers
to release gsmttyB's ld data dlci[B], then race would happen if gsmttyB
is opening in parallel.
(Note: This patch set differs from previous set in that it uses mutex
instead of spin lock to avoid race, so that it avoids sleeping in automic
context)
Here are race cases we found recently in test:
CASE #1
====================================================================
releasing dlci[B] race with gsmtty_install(gsmttyB), then panic
in gsmtty_open(gsmttyB), as below:
tty_release(ttyA) tty_open(gsmttyB)
| |
----- gsmtty_install(gsmttyB)
| |
----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B]
tty_ldisc_release(ttyA) -----
| |
gsm_dlci_release(dlci[B]) -----
| |
gsm_dlci_free(dlci[B]) -----
| |
----- gsmtty_open(gsmttyB)
gsmtty_open()
{
struct gsm_dlci *dlci = tty->driver_data; => here it uses dlci[B]
...
}
In gsmtty_open(gsmttyA), it uses dlci[B] which was release, so hit a panic.
=====================================================================
CASE #2
=====================================================================
releasing dlci[0] race with gsmtty_install(gsmttyB), then panic
in gsmtty_open(), as below:
tty_release(ttyA) tty_open(gsmttyB)
| |
----- gsmtty_install(gsmttyB)
| |
----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B]
| |
----- gsmtty_open(gsmttyB) fail
| |
----- tty_release(gsmttyB)
| |
----- gsmtty_close(gsmttyB)
| |
----- gsmtty_detach_dlci(dlci[B])
| |
----- dlci_put(dlci[B])
| |
tty_ldisc_release(ttyA) -----
| |
gsm_dlci_release(dlci[0]) -----
| |
gsm_dlci_free(dlci[0]) -----
| |
----- dlci_put(dlci[0])
In gsmtty_detach_dlci(dlci[B]), it tries to use dlci[0] which was released,
then hit panic.
=====================================================================
IMHO, n_gsm tty operations would refer released ldisc, as long as
gsm_dlci_release() has chance to release ldisc data when some gsmtty operations
are ongoing..
This patch is try to avoid it by:
1) in n_gsm driver, use a global gsm mutex lock to avoid gsm_dlci_release() run in
parallel with gsmtty_install();
2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the
purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install()
allocats dlci but before gsmtty_open increases dlci's ref count;
3) Decrease dlci's ref count in gsmtty_remove(), a tty framework API, this is the
opposite process of step 2).
Signed-off-by: Chao Bi <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
