Commit Graph

4438 Commits

Author SHA1 Message Date
Akinobu Mita 802c03881f sysrq: attach sysrq handler correctly for 32-bit kernel
The sysrq input handler should be attached to the input device which has
a left alt key.

On 32-bit kernels, some input devices which has a left alt key cannot
attach sysrq handler.  Because the keybit bitmap in struct input_device_id
for sysrq is not correctly initialized.  KEY_LEFTALT is 56 which is
greater than BITS_PER_LONG on 32-bit kernels.

I found this problem when using a matrix keypad device which defines
a KEY_LEFTALT (56) but doesn't have a KEY_O (24 == 56%32).

Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 09:22:54 +01:00
Herbert Xu 6741f551a0 Revert "tty: serial: 8250: add CON_CONSDEV to flags"
This commit needs to be reverted because it prevents people from
using the serial console as a secondary console with input being
directed to tty0.

IOW, if you boot with console=ttyS0 console=tty0 then all kernels
prior to this commit will produce output on both ttyS0 and tty0
but input will only be taken from tty0.  With this patch the serial
console will always be the primary console instead of tty0,
potentially preventing people from getting into their machines in
emergency situations.

Fixes: d03516df83 ("tty: serial: 8250: add CON_CONSDEV to flags")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 08:35:17 +01:00
Daniel Jedrychowski 2bed8a8e70 Clearing FIFOs in RS485 emulation mode causes subsequent transmits to break
When in RS485 emulation mode, __do_stop_tx_rs485() calls
serial8250_clear_fifos().  This not only clears the FIFOs, but also sets
all bits in their control register (UART_FCR) to 0.

One of the effects of this is the disabling of the FIFOs, which turns
them into single-byte holding registers.  The rest of the driver doesn't
know this, which results in the lions share of characters passed into a
write call to be dropped.

(I can supply logic analyzer screenshots if necessary)

This fix replaces the serial8250_clear_fifos() call to
serial8250_clear_and_reinit_fifos() - this prevents the "dropped
characters" issue from manifesting again while retaining the requirement
of clearing the RX FIFO after transmission if the SER_RS485_RX_DURING_TX
flag is disabled.

Signed-off-by: Daniel Jedrychowski <avistel@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 08:35:17 +01:00
Gabriel Krisman Bertazi c130b666a9 8250_pci: Fix potential use-after-free in error path
Commit f209fa03fc ("serial: 8250_pci: Detach low-level driver during
PCI error recovery") introduces a potential use-after-free in case the
pciserial_init_ports call in serial8250_io_resume fails, which may
happen if a memory allocation fails or if the .init quirk failed for
whatever reason).  If this happen, further pci_get_drvdata will return a
pointer to freed memory.

This patch reworks the PCI recovery resume hook to restore the old priv
structure in this case, which should be ok, since the ports were already
detached. Such error during recovery causes us to give up on the
recovery.

Fixes: f209fa03fc ("serial: 8250_pci: Detach low-level driver during
  PCI error recovery")
Reported-by: Michal Suchanek <msuchanek@suse.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 08:35:17 +01:00
Richard Genoud b389f173aa tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done
When using RS485 in half duplex, RX should be enabled when TX is
finished, and stopped when TX starts.

Before commit 0058f0871e ("tty/serial: atmel: fix RS485 half
duplex with DMA"), RX was not disabled in atmel_start_tx() if the DMA
was used. So, collisions could happened.

But disabling RX in atmel_start_tx() uncovered another bug:
RX was enabled again in the wrong place (in atmel_tx_dma) instead of
being enabled when TX is finished (in atmel_complete_tx_dma), so the
transmission simply stopped.

This bug was not triggered before commit 0058f0871e
("tty/serial: atmel: fix RS485 half duplex with DMA") because RX was
never disabled before.

Moving atmel_start_rx() in atmel_complete_tx_dma() corrects the problem.

Cc: stable@vger.kernel.org
Reported-by: Gil Weber <webergil@gmail.com>
Fixes: 0058f0871e
Tested-by: Gil Weber <webergil@gmail.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 08:18:45 +01:00
Richard Genoud 89d8232411 tty/serial: atmel_serial: BUG: stop DMA from transmitting in stop_tx
If we don't disable the transmitter in atmel_stop_tx, the DMA buffer
continues to send data until it is emptied.
This cause problems with the flow control (CTS is asserted and data are
still sent).

So, disabling the transmitter in atmel_stop_tx is a sane thing to do.

Tested on at91sam9g35-cm(DMA)
Tested for regressions on sama5d2-xplained(Fifo) and at91sam9g20ek(PDC)

Cc: <stable@vger.kernel.org> (beware, this won't apply before 4.3)
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 08:18:45 +01:00
Linus Torvalds 7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Linus Torvalds e3842cbfe0 dmaengine updates for 4.10-rc1
Fairly routine update this time around with all changes specific to drivers.
 
  o New driver for STMicroelectronics FDMA
  o Memory-to-memory transfers on dw dmac
  o Support for slave maps on pl08x devices
  o Bunch of driver fixes to use dma_pool_zalloc
  o Bunch of compile and warning fixes spread across drivers
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJYUg7NAAoJEHwUBw8lI4NH5/gP/j81+2RzCUX8PiLQxNUt0Vj+
 tVJEizpWCwN1cnhc8ibZdI1DAwyj+GbN2lghYTjqqEng4yOm3czPzUl99grBrpQl
 t+Qylr9PSpck/paRhd2lgZzG8Nk+B5HJDcxBQbW4pwmbc69YAbqYzt44i4bDpR5K
 u3mBve1Ulng7peP45EZB8BA32ffCpOEAC/9SdkaPokrSv6XxxPEFvzewy+mLtioU
 a0zY0iuHqVGpOTABK65fXO/zkGiZLPXJ1T5vK7Iz8mOwuvtYVif0yktQSrx3BWbc
 9r64W7Si633wWt/C9LkuMMSmQ7nI/PyHk811cDOcxp3SA79JV5SWwdQl+5QPdtoP
 hyToaISfAY0BiNI9ltdscx3MPjlwSp08xXvi46RjSs8E2TXnbHUw+J5mTsxYuocl
 Yi61nlL5ClhCbySf9Q3GFsuAJ3O2Nq9WkCTNRIvJtrMhe3NeqDDTfBZJRD4Bfg1G
 q8RAc5oqGZDtqKHtLfwULr7Ec2Ru0hIZAyN907OwW+4jBR/eBJB1y+nGrNPtTWPT
 OOcvrxe85/+ZNROGCZKr0L8UA/MBBMZtjvMY8RMXjBE4YJbakq7tV+7l5VolKeNH
 G6I/1CC06qVPHrnetM6YejhtnmOQ4F8P1sE0wvpG0QTyHJoFq+aOhHNKJC8F9Eln
 CQM2apvL4BHvS7OHt9XL
 =Pf0d
 -----END PGP SIGNATURE-----

Merge tag 'dmaengine-4.10-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:
 "Fairly routine update this time around with all changes specific to
  drivers:

   - New driver for STMicroelectronics FDMA
   - Memory-to-memory transfers on dw dmac
   - Support for slave maps on pl08x devices
   - Bunch of driver fixes to use dma_pool_zalloc
   - Bunch of compile and warning fixes spread across drivers"

[ The ST FDMA driver already came in earlier through the remoteproc tree ]

* tag 'dmaengine-4.10-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
  dmaengine: sirf-dma: remove unused ‘sdesc’
  dmaengine: pl330: remove unused ‘regs’
  dmaengine: s3c24xx: remove unused ‘cdata’
  dmaengine: stm32-dma: remove unused ‘src_addr’
  dmaengine: stm32-dma: remove unused ‘dst_addr’
  dmaengine: stm32-dma: remove unused ‘sfcr’
  dmaengine: pch_dma: remove unused ‘cookie’
  dmaengine: mic_x100_dma: remove unused ‘data’
  dmaengine: img-mdc: remove unused ‘prev_phys’
  dmaengine: usb-dmac: remove unused ‘uchan’
  dmaengine: ioat: remove unused ‘res’
  dmaengine: ioat: remove unused ‘ioat_dma’
  dmaengine: ioat: remove unused ‘is_raid_device’
  dmaengine: pl330: do not generate unaligned access
  dmaengine: k3dma: move to dma_pool_zalloc
  dmaengine: at_hdmac: move to dma_pool_zalloc
  dmaengine: at_xdmac: don't restore unsaved status
  dmaengine: ioat: set error code on failures
  dmaengine: ioat: set error code on failures
  dmaengine: DW DMAC: add multi-block property to device tree
  ...
2016-12-14 20:42:45 -08:00
Linus Torvalds c11a6cfb01 Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Mostly patches to initialize workqueue subsystem earlier and get rid
  of keventd_up().

  The patches were headed for the last merge cycle but got delayed due
  to a bug found late minute, which is fixed now.

  Also, to help debugging, destroy_workqueue() is more chatty now on a
  sanity check failure."

* 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: move wq_numa_init() to workqueue_init()
  workqueue: remove keventd_up()
  debugobj, workqueue: remove keventd_up() usage
  slab, workqueue: remove keventd_up() usage
  power, workqueue: remove keventd_up() usage
  tty, workqueue: remove keventd_up() usage
  mce, workqueue: remove keventd_up() usage
  workqueue: make workqueue available early during boot
  workqueue: dump workqueue state on sanity check failures in destroy_workqueue()
2016-12-13 12:59:57 -08:00
Linus Torvalds 5266e70335 TTY/Serial patches for 4.10-rc1
Here's the tty/serial patchset for 4.10-rc1.
 
 It's been a quiet kernel cycle for this subsystem, just a small number
 of changes.  A few new serial drivers, and some cleanups to the old
 vgacon logic, and other minor serial driver changes as well.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWFAwDQ8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylcngCgko5+aPLnHENLNIaHhHlfdMbhy+EAn2H8wkzY
 bEf+BG4CJDb6nZWERcUQ
 =STpQ
 -----END PGP SIGNATURE-----

Merge tag 'tty-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here's the tty/serial patchset for 4.10-rc1.

  It's been a quiet kernel cycle for this subsystem, just a small number
  of changes. A few new serial drivers, and some cleanups to the old
  vgacon logic, and other minor serial driver changes as well.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (54 commits)
  serial: 8250_mid fix calltrace when hotplug 8250 serial controller
  console: Move userspace I/O out of console_lock to fix lockdep warning
  tty: nozomi: avoid sprintf buffer overflow
  serial: 8250_pci: Detach low-level driver during PCI error recovery
  serial: core: don't check port twice in a row
  mxs-auart: count FIFO overrun errors
  serial: 8250_dw: Add support for IrDA SIR mode
  serial: 8250: Expose set_ldisc function
  serial: 8250: Add IrDA to UART capabilities
  serial: 8250_dma: power off device after TX is done
  serial: 8250_port: export serial8250_rpm_{get|put}_tx()
  serial: sunsu: Free memory when probe fails
  serial: sunhv: Free memory when remove() is called
  vt: fix Scroll Lock LED trigger name
  tty: typo in comments in drivers/tty/vt/keyboard.c
  tty: amba-pl011: Add earlycon support for SBSA UART
  tty: nozomi: use permission-specific DEVICE_ATTR variants
  tty: serial: Make the STM32 serial port depend on it's arch
  serial: ifx6x60: Free memory when probe fails
  serial: ioc4_serial: Free memory when kzalloc fails during probe
  ...
2016-12-13 11:18:24 -08:00
Linus Torvalds 8fa3b6f939 Three patches for minor issues:
Guenter Roeck (1):
       cris: Only build flash rescue image if CONFIG_ETRAX_AXISFLASHMAP is selected
 
 Paul Bolle (1):
       cris: No need to append -O2 and $(LINUXINCLUDE)
 
 Paul Gortmaker (1):
       tty: serial: make crisv10 explicitly non-modular
 
  arch/cris/boot/compressed/Makefile |    3 ---
  arch/cris/boot/rescue/Makefile     |    9 +++++++--
  drivers/tty/serial/crisv10.c       |    6 ++----
  3 files changed, 9 insertions(+), 9 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iEYEABECAAYFAlhJbl0ACgkQ31LbvUHyf1cK3QCfTFKWF21o02/H8ZFby6oa7Jgp
 X4kAn0+rFwV0CtJ3JQum49DsHZf/M72+
 =iH+I
 -----END PGP SIGNATURE-----

Merge tag 'cris-for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris

Pull CRIS updates from Jesper Nilsson:
 "Three patches for minor issues"

* tag 'cris-for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
  cris: No need to append -O2 and $(LINUXINCLUDE)
  tty: serial: make crisv10 explicitly non-modular
  cris: Only build flash rescue image if CONFIG_ETRAX_AXISFLASHMAP is selected
2016-12-12 09:06:38 -08:00
Liwei Song a9b01b5823 serial: 8250_mid fix calltrace when hotplug 8250 serial controller
Fix the following Calltrace:
[   77.768221] WARNING: CPU: 5 PID: 645 at drivers/dma/dmaengine.c:1069 dma_async_device_unregister+0xe2/0xf0
[   77.775058] dma_async_device_unregister called while 1 clients hold a reference
[   77.825048] CPU: 5 PID: 645 Comm: sh Not tainted 4.8.8-WR9.0.0.0_standard+ #3
[   77.832550] Hardware name: Intel Corp. Aspen Cove/Server, BIOS HAVLCRB1.X64.0012.D58.1604140405 04/14/2016
[   77.840396]  0000000000000000 ffffc90008adbc80 ffffffff81403456 ffffc90008adbcd0
[   77.848245]  0000000000000000 ffffc90008adbcc0 ffffffff8105e2e1 0000042d08adbf20
[   77.855934]  ffff88046a861c18 ffff88046a85c420 ffffffff820d4200 ffff88046ae92318
[   77.863601] Call Trace:
[   77.871113]  [<ffffffff81403456>] dump_stack+0x4f/0x69
[   77.878655]  [<ffffffff8105e2e1>] __warn+0xd1/0xf0
[   77.886102]  [<ffffffff8105e34f>] warn_slowpath_fmt+0x4f/0x60
[   77.893508]  [<ffffffff814187a9>] ? find_next_bit+0x19/0x20
[   77.900730]  [<ffffffff814bf83e>] ? dma_channel_rebalance+0x23e/0x270
[   77.907814]  [<ffffffff814bfee2>] dma_async_device_unregister+0xe2/0xf0
[   77.914992]  [<ffffffff814c53aa>] hsu_dma_remove+0x1a/0x60
[   77.921977]  [<ffffffff814ee14c>] dnv_exit+0x1c/0x20
[   77.928752]  [<ffffffff814edff6>] mid8250_remove+0x26/0x40
[   77.935607]  [<ffffffff8144f1b9>] pci_device_remove+0x39/0xc0
[   77.942292]  [<ffffffff8160cfea>] __device_release_driver+0x9a/0x140
[   77.948836]  [<ffffffff8160d0b3>] device_release_driver+0x23/0x30
[   77.955364]  [<ffffffff81447dcc>] pci_stop_bus_device+0x8c/0xa0
[   77.961769]  [<ffffffff81447f0a>] pci_stop_and_remove_bus_device_locked+0x1a/0x30
[   77.968113]  [<ffffffff81450d4e>] remove_store+0x5e/0x70
[   77.974267]  [<ffffffff81607ed8>] dev_attr_store+0x18/0x30
[   77.980243]  [<ffffffff8123006a>] sysfs_kf_write+0x3a/0x50
[   77.986180]  [<ffffffff8122f5ab>] kernfs_fop_write+0x10b/0x190
[   77.992118]  [<ffffffff811bf1c8>] __vfs_write+0x18/0x40
[   77.998032]  [<ffffffff811bfdee>] vfs_write+0xae/0x190
[   78.003747]  [<ffffffff811c1016>] SyS_write+0x46/0xb0
[   78.009234]  [<ffffffff81a4c31b>] entry_SYSCALL_64_fastpath+0x13/0x8f
[   78.014809] ---[ end trace 0c36dd73b7408eb2 ]---

This happens when the 8250 serial controller is hotplugged as follows:
echo 1 > /sys/bus/pci/devices/0000:00:1a.0/remove

This trace happens due to the serial port still holding a reference when
the dma device is unregistered.
The dma unregister routine will check if there is still a reference exist,
if so it will give the WARNING(here serial port still was not unregister).

To fix this, We need to unregister the serial port first, then do DMA
device unregister to make sure there is no reference when to DMA routine.

Signed-off-by: Liwei Song <liwei.song@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-30 13:06:08 +01:00
Eugeniy Paltsev bd2c6636cc dmaengine: DW DMAC: add multi-block property to device tree
Several versions of DW DMAC have multi block transfers hardware
support. Hardware support of multi block transfers is disabled
by default if we use DT to configure DMAC and software emulation
of multi block transfers used instead.
Add multi-block property, so it is possible to enable hardware
multi block transfers (if present) via DT.

Switch from per device is_nollp variable to multi_block array
to be able enable/disable multi block transfers separately per
channel.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-30 08:57:50 +05:30
Waiman Long 7edd7e82b9 console: Move userspace I/O out of console_lock to fix lockdep warning
When running certain workload on a debug kernel with lockdep turned on,
a ppc64 kvm guest could sometimes hit the following lockdep warning:

  [ INFO: possible circular locking dependency detected ]
  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&mm->mmap_sem);
                                lock(console_lock);
                                lock(&mm->mmap_sem);
   lock(cpu_hotplug.lock);

  *** DEADLOCK ***

Looking at the console code, the console_lock-->mmap_sem scenario will
only happen when reading or writing the console unicode map leading to
a page fault.

To break this circular locking dependency, all the userspace I/O
operations in consolemap.c are now moved outside of the console_lock
critical sections so that the mmap_sem won't be acquired when holding
the console_lock.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29 21:42:40 +01:00
Arnd Bergmann 5020ded783 tty: nozomi: avoid sprintf buffer overflow
Testing with a gcc-7 snapshot produced an internal compiler error
for this file:

drivers/tty/nozomi.c: In function 'receive_flow_control':
drivers/tty/nozomi.c:919:12: internal compiler error: in get_substring_ranges_for_loc, at input.c:1388
 static int receive_flow_control(struct nozomi *dc)

I've reported this at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78569
but also noticed that the code line contains a stack overflow, as it prints
a string into a slightly shorter fixed-length 'tmp' variable.

A lot of the code here is unnecessary and can be expressed in a simpler
way, relying on the fact that removing the 'DEBUG' macro will also get
rid of all pr_debug() calls. This change should not change any of the
output but avoids both the stack overflow and the gcc crash.

The stack overflow will not happen unless a module load parameter is
also set to enable the debug messages.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29 20:20:07 +01:00
Gabriel Krisman Bertazi f209fa03fc serial: 8250_pci: Detach low-level driver during PCI error recovery
During a PCI error recovery, like the ones provoked by EEH in the ppc64
platform, all IO to the device must be blocked while the recovery is
completed.  Current 8250_pci implementation only suspends the port
instead of detaching it, which doesn't prevent incoming accesses like
TIOCMGET and TIOCMSET calls from reaching the device.  Those end up
racing with the EEH recovery, crashing it.  Similar races were also
observed when opening the device and when shutting it down during
recovery.

This patch implements a more robust IO blockage for the 8250_pci
recovery by unregistering the port at the beginning of the procedure and
re-adding it afterwards.  Since the port is detached from the uart
layer, we can be sure that no request will make through to the device
during recovery.  This is similar to the solution used by the JSM serial
driver.

I thank Peter Hurley <peter@hurleysoftware.com> for valuable input on
this one over one year ago.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29 20:20:07 +01:00
Andy Shevchenko ef510bea5f serial: core: don't check port twice in a row
There is no need to check port for NULL in uart_port_deref() since we call it
only when port is defined.

There are few places that violate this. Fix them here as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-28 08:29:34 +01:00
Wolfgang Ocker b810645473 mxs-auart: count FIFO overrun errors
The mxs-auart driver does not count FIFO overrun errors. These errors never
appear in /proc/tty/driver/ttyAPP. This is because the OERR status bit is
masked by read_status_mask in the rx interrupt function, but the
AUART_STAT_OERR bit is never set in read_status_mask. The patch enables the
counting of overrun errors.

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 17:17:42 +01:00
Ed Blake 0e0b989eb3 serial: 8250_dw: Add support for IrDA SIR mode
Add a set_ldisc function to enable/disable IrDA SIR mode according to
the new line discipline, if IrDA SIR mode is supported by the hardware
configuration.

Signed-off-by: Ed Blake <ed.blake@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:59:38 +01:00
Ed Blake db405a8f8b serial: 8250: Expose set_ldisc function
Expose set_ldisc() function so that it can be overridden with a
platform specific implementation.

Signed-off-by: Ed Blake <ed.blake@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:59:38 +01:00
Ed Blake 98838d9507 serial: 8250: Add IrDA to UART capabilities
Add an IrDA UART capability flag and change the type of
uart_8250_port.capabilities to be u32 rather than unsigned short to
accommodate the additional flag.

Signed-off-by: Ed Blake <ed.blake@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:59:38 +01:00
Andy Shevchenko 5fe8667484 serial: 8250_dma: power off device after TX is done
When any 8250 based driver sets up DMA and has UART_CAP_RPM capability enabled
the device is left powered on after transfer is done. We need to schedule a
device suspend operation when DMA completes the transfer.

The patch is based on the work done by the reporter.

Reported-by: Huiquan Zhong <huiquan.zhong@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:57:26 +01:00
Andy Shevchenko 7d4e00c625 serial: 8250_port: export serial8250_rpm_{get|put}_tx()
The following fix of runtime PM use in DMA mode requires at least
serial8250_rpm_put_tx() to be available. Export both calls.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:57:26 +01:00
Souptick Joarder af6f9d6883 serial: sunsu: Free memory when probe fails
When su_probe() fails it doesn't free *up and we may have a memory
leak. Fix this by freeing *up before return.

Signed-off-by: Souptick joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:57:26 +01:00
Souptick Joarder fbb7d2e3a9 serial: sunhv: Free memory when remove() is called
In each call to hv_remove(), con_read_page and con_write_page is not
getting freed and lead to memory leakage. Fix this by freeing both
pointers in hv_remove().

Signed-off-by: Souptick joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:57:25 +01:00
Maciej S. Szmigiero 31b5929d53 vt: fix Scroll Lock LED trigger name
There is a disagreement between drivers/tty/vt/keyboard.c and
drivers/input/input-leds.c with regard to what is a Scroll Lock LED
trigger name: input calls it "kbd-scrolllock", but vt calls it
"kbd-scrollock" (two l's).
This prevents Scroll Lock LED trigger from binding to this LED by default.

Since it is a scroLL Lock LED, this interface was introduced only about a
year ago and in an Internet search people seem to reference this trigger
only to set it to this LED let's simply rename it to "kbd-scrolllock".

Also, it looks like this was supposed to be changed before this code was
merged: https://lkml.org/lkml/2015/6/9/697 but it was done only on
the input side.

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: stable <stable@vger.kernel.org> # 4.2+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-16 10:03:52 +01:00
Askar Safin 26ba68d2f8 tty: typo in comments in drivers/tty/vt/keyboard.c
Fixed typo in comments in drivers/tty/vt/keyboard.c

Signed-off-by: Askar Safin <safinaskar@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 15:10:37 +01:00
Kefeng Wang fcb321590c tty: amba-pl011: Add earlycon support for SBSA UART
Declare an OF early console for SBSA UART so that the early console device
can be specified via the "stdout-path" property in device-tree.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 15:10:37 +01:00
Julia Lawall 19467fa179 tty: nozomi: use permission-specific DEVICE_ATTR variants
Use DEVICE_ATTR_RO for read only attributes.  This simplifies the
source code, improves readbility, and reduces the chance of
inconsistencies.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@ro@
declarer name DEVICE_ATTR;
identifier x,x_show;
@@

DEVICE_ATTR(x, \(0444\|S_IRUGO\), x_show, NULL);

@script:ocaml@
x << ro.x;
x_show << ro.x_show;
@@

if not (x^"_show" = x_show) then Coccilib.include_match false

@@
declarer name DEVICE_ATTR_RO;
identifier ro.x,ro.x_show;
@@

- DEVICE_ATTR(x, \(0444\|S_IRUGO\), x_show, NULL);
+ DEVICE_ATTR_RO(x);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 15:10:37 +01:00
Peter Robinson adcb05f01f tty: serial: Make the STM32 serial port depend on it's arch
The STM32 serial port is SoC specific so no point enabling it
without the architecture enabled.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 15:01:15 +01:00
Souptick Joarder 0a940b0d25 serial: ifx6x60: Free memory when probe fails
When spi_setup() fails it doesn't free ifx_dev and we have a memory
leak. Fix this by freeing ifx_dev before the return.

Signed-off-by: Souptick joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:50:46 +01:00
Souptick Joarder 7f8b4ebeb2 serial: ioc4_serial: Free memory when kzalloc fails during probe
Inside ioc4_attach_local() 4 memory was allocated using kzalloc and
assign it to ports[] within loop. When kzalloc fails inside loop,
it returns error without freeing previously allocated memory and we
may have memory leak. Fix this by freeing ports[] before return.

Signed-off-by: Souptick joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:50:46 +01:00
Arnd Bergmann 65dabaf532 serial: pxa2xx: mark PM functions as __maybe_unused
The fresh new serial driver for pxa produces warnings when
CONFIG_PM_SLEEP is disabled:

drivers/tty/serial/8250/8250_pxa.c:50:12: error: 'serial_pxa_resume' defined but not used [-Werror=unused-function]
drivers/tty/serial/8250/8250_pxa.c:41:12: error: 'serial_pxa_suspend' defined but not used [-Werror=unused-function]

This removes the #ifdef around the two functions and instead marks both
as __maybe_unused, which is more robust and avoids the warning.

Fixes: ab28f51c77 ("serial: rewrite pxa2xx-uart to use 8250_core")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:50:46 +01:00
Arnd Bergmann 9de4153dbb serial: pxa2xx: remove __deprecated annotation
An otherwise very nice cleanup of the pxa2xx uart support marked the
init function of this driver as __deprecated:

drivers/tty/serial/pxa.c:944:1: error: 'serial_pxa_init' is deprecated [-Werror=deprecated-declarations]

This seems unhelpful to me, as we now warn for every allmodconfig build,
which is otherwise free of warnings on most architectures. Let's
remove the annotation again.

Fixes: ab28f51c77 ("serial: rewrite pxa2xx-uart to use 8250_core")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:50:45 +01:00
Johan Hovold 68832b20c9 serial: crisv10: fix invalid user-pointer check
Drop invalid user-pointer check from TIOCGSERIAL handler.

A NULL-pointer can be valid in user space and copy_to_user() takes care
of sanity checking.

Cc: Mikael Starvik <starvik@axis.com>
Cc: linux-cris-kernel@axis.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:41:25 +01:00
Johan Hovold 7a3f09846c tty: rocket: fix invalid user-pointer checks
Drop invalid user-pointer checks from custom ioctl handlers.

A NULL-pointer can be valid in user space and copy_to_user() takes care
of sanity checking.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:41:25 +01:00
Johan Hovold 6f8ada1292 tty: amiserial: fix invalid user-pointer check
Drop invalid user-pointer check from TIOCGSERIAL handler.

A NULL-pointer can be valid in user space and copy_to_user() takes care
of sanity checking.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:41:25 +01:00
Angelo Butti 5c31ef91c0 8250: FIX Fourth port offset of Pericom PI7C9X7954 boards
Hi,
below patch to fix Fourth port offset of Percom PI7C9X7954 boards.

I had a problem using Fourth port on a pci express serial board based on Pericom
PI7C9X7954. Reading datasheet I notice a "special" offset assign to this port
when used in I/O mode.

Offset 0x0 ->  UART 0
Offset 0x8 ->  UART 1
Offset 0x10 ->  UART 2
Offset 0x38 ->  UART 3  <<---- This don't follow a logical sequence

This patch add a different init to last port, to have right offset.

I check also Pericom 7952 and 7958 but that devices follow logical sequence,
so they are ok.

Regards,
Angelo

Signed-off-by: Angelo Butti <buttiangelo@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:41:25 +01:00
Takatoshi Akiyama 6fc5a52042 serial: sh-sci: Fix deadlock caused by serial output request
While spin is already locked, serial output request causes the deadlock,
because serial output process also tries to lock the spin.
This patch removes serial output with spin locked.

Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:39:44 +01:00
Paul Gortmaker 146b4d5b36 tty: serial: make crisv10 explicitly non-modular
The Kconfig currently controlling compilation of this code is:

arch/cris/arch-v10/drivers/Kconfig:config ETRAX_SERIAL
arch/cris/arch-v10/drivers/Kconfig:     bool "Serial-port support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.

Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-cris-kernel@axis.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:34:27 +01:00
Arnd Bergmann 9211432b4a serial: 8250_pxa: hide early console setup when disabled
The newly added pxa glue driver for 8250 supports console output, but
fails to build if the 8250 console is disabled:

drivers/tty/serial/8250/8250_pxa.o: In function `early_serial_pxa_setup':
8250_pxa.c:(.init.text+0x50): undefined reference to `early_serial8250_setup'

This adds an #ifdef like the other glue drivers have it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:34:27 +01:00
Masahiro Yamada da7fa058a3 serial: 8250_uniphier: avoid locking for FCR register write
The hardware book says, the FCR is combined with a register called
CHAR (it will trigger interrupt when a specific character is
received).  At first, I used lock/read/modify/write/unlock dance for
the FCR to not affect the upper bits, but the CHAR is actually never
used.  It should not hurt to always clear the CHAR and to handle the
FCR as a normal case.  It can save the costly locking.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:30:09 +01:00
Masahiro Yamada 94cbb6978b serial: 8250_uniphier: hardcode regshift to avoid unneeded memory read
For this driver, uart_port::regshift is always 2.  Hardcode the
shift value instead of reading ->regshift to get an already known
value.  (pointed out by Denys Vlasenko)

Furthermore, I am using register macros that are already shifted,
which will save code a bit.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10 14:30:08 +01:00
Paul Gortmaker c78874f116 tty: serial: make crisv10 explicitly non-modular
The Kconfig currently controlling compilation of this code is:

arch/cris/arch-v10/drivers/Kconfig:config ETRAX_SERIAL
arch/cris/arch-v10/drivers/Kconfig:     bool "Serial-port support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.

Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-cris-kernel@axis.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
2016-11-07 11:47:19 +01:00
David S. Miller 27058af401 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Mostly simple overlapping changes.

For example, David Ahern's adjacency list revamp in 'net-next'
conflicted with an adjacency list traversal bug fix in 'net'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-30 12:42:58 -04:00
Greg Kroah-Hartman 5131dcd781 Merge 4.9-rc3 into tty-next
We want the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-30 06:42:10 -04:00
Rob Herring d0f4bce2bc tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeup
Since commit 761ed4a945 ("tty: serial_core: convert uart_close to
use tty_port_close"), the serial console is broken on various systems
and typing "reboot" splats the following on the serial console:

INIT: Sending p[  427.863916] BUG: unable to handle kernel NULL pointer dereference at 00000000000001e0
[  427.885156] IP: [] tty_wakeup+0xc/0x70
[  427.898337] PGD 0 [  427.902051]
[  427.907498] Oops: 0000 [#1] PREEMPT SMP
[  427.917635] Modules linked in: nfsv3 nfs_acl nfs fscache lockd
sunrpc grace edd af_packet cpufreq_conservative cpufreq_userspace
cpufreq_powersave fuse loop md_mod dm_mod joydev hid_generic usbhid
ipmi_ssif ohci_pci ohci_hcd ehci_pci ehci_hcd e1000e ptp firewire_ohci
edac_core pps_core tpm_infineon sp5100_tco firewire_core acpi_cpufreq
serio_raw pcspkr fjes usbcore shpchp edac_mce_amd tpm_tis ipmi_si
tpm_tis_core i2c_piix4 k10temp sg ipmi_msghandler tpm sr_mod button
cdrom kvm_amd kvm irqbypass crc_itu_t ast ttm drm_kms_helper drm
fb_sys_fops sysimgblt sysfillrect syscopyarea i2c_algo_bit scsi_dh_rdac
scsi_dh_alua scsi_dh_emc scsi_dh_hp_sw ata_generic pata_atiixp
[  428.054179] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc1-1.g73e3f23-default #1
[  428.072868] Hardware name: System manufacturer System Product Name/KGP(M)E-D16, BIOS 0902    12/03/2010
[  428.094755] task: ffffffffa2c0d500 task.stack: ffffffffa2c00000
[  428.109717] RIP: 0010:[]  [] tty_wakeup+0xc/0x70
[  428.128407] RSP: 0018:ffff9a1a5fc03df8  EFLAGS: 00010086
[  428.142184] RAX: ffff9a1857258000 RBX: ffffffffa3050ea0 RCX: 0000000000000000
[  428.159649] RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000000
[  428.177109] RBP: ffff9a1a5fc03e08 R08: 0000000000000000 R09: 0000000000000000
[  428.194547] R10: 0000000000021c77 R11: 0000000000000000 R12: ffff9a1857258000
[  428.212002] R13: 0000000000000000 R14: 0000000000000020 R15: 0000000000000020
[  428.229481] FS:  0000000000000000(0000) GS:ffff9a1a5fc00000(0000) knlGS:0000000000000000
[  428.248938] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  428.263726] CR2: 00000000000001e0 CR3: 0000000390c06000 CR4: 00000000000006f0
[  428.281331] Stack:
[  428.288696]  ffffffffa3050ea0 ffff9a1857258000 ffff9a1a5fc03e18 ffffffffa24e0ab1
[  428.307064]  ffff9a1a5fc03e40 ffffffffa24e8865 ffffffffa3050ea0 00000000000000c2
[  428.325456]  0000000000000046 ffff9a1a5fc03e78 ffffffffa24e8a5f ffffffffa3050ea0
[  428.343905] Call Trace:
[  428.352319]   [  428.356216]  [] uart_write_wakeup+0x21/0x30

The problem is for console ports, the serial port is not shutdown and
interrupts may fire after the struct tty is gone. Simply calling the
tty_port helper tty_port_tty_wakeup instead of tty_wakeup directly will
ensure there is a valid struct tty.

Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Mike Galbraith <mgalbraith@suse.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:13:07 -04:00
Geert Uytterhoeven 4dda864d73 tty: serial_core: Fix serial console crash on port shutdown
The port->console flag is always false, as uart_console() is called
before the serial console has been registered.

Hence for a serial port used as the console, uart_tty_port_shutdown()
will still be called when userspace closes the port, powering it down.
This may lead to a system lock up when the serial console driver writes
to the serial port's registers.

To fix this, move the setting of port->console after the call to
uart_configure_port(), which registers the serial console.

Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Mugunthan V N <mugunthanvnm@ti.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
[robh: rebased on tty-linus]
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:13:07 -04:00
Richard Genoud 9bcffe7575 tty/serial: at91: fix hardware handshake on Atmel platforms
After commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), the hardware handshake wasn't
functional anymore on Atmel platforms (beside SAMA5D2).

To understand why, one has to understand the flag ATMEL_US_USMODE_HWHS
first:
Before commit 1cf6e8fc83 ("tty/serial: at91: fix RTS line management
when hardware handshake is enabled"), this flag was never set.
Thus, the CTS/RTS where only handled by serial_core (and everything
worked just fine).

This commit introduced the use of the ATMEL_US_USMODE_HWHS flag,
enabling it for all boards when the user space enables flow control.

When the ATMEL_US_USMODE_HWHS is set, the Atmel USART controller
handles a part of the flow control job:
- disable the transmitter when the CTS pin gets high.
- drive the RTS pin high when the DMA buffer transfer is completed or
  PDC RX buffer full or RX FIFO is beyond threshold. (depending on the
  controller version).

NB: This feature is *not* mandatory for the flow control to work.
(Nevertheless, it's very useful if low latencies are needed.)

Now, the specifics of the ATMEL_US_USMODE_HWHS flag:

- For platforms with DMAC and no FIFOs (sam9x25, sam9x35, sama5D3,
sama5D4, sam9g15, sam9g25, sam9g35)* this feature simply doesn't work.
( source: https://lkml.org/lkml/2016/9/7/598 )
Tested it on sam9g35, the RTS pins always stays up, even when RXEN=1
or a new DMA transfer descriptor is set.
=> ATMEL_US_USMODE_HWHS must not be used for those platforms

- For platforms with a PDC (sam926{0,1,3}, sam9g10, sam9g20, sam9g45,
sam9g46)*, there's another kind of problem. Once the flag
ATMEL_US_USMODE_HWHS is set, the RTS pin can't be driven anymore via
RTSEN/RTSDIS in USART Control Register. The RTS pin can only be driven
by enabling/disabling the receiver or setting RCR=RNCR=0 in the PDC
(Receive (Next) Counter Register).
=> Doing this is beyond the scope of this patch and could add other
bugs, so the original (and working) behaviour should be set for those
platforms (meaning ATMEL_US_USMODE_HWHS flag should be unset).

- For platforms with a FIFO (sama5d2)*, the RTS pin is driven according
to the RX FIFO thresholds, and can be also driven by RTSEN/RTSDIS in
USART Control Register. No problem here.
(This was the use case of commit 1cf6e8fc83 ("tty/serial: at91: fix
RTS line management when hardware handshake is enabled"))
NB: If the CTS pin declared as a GPIO in the DTS, (for instance
cts-gpios = <&pioA PIN_PB31 GPIO_ACTIVE_LOW>), the transmitter will be
disabled.
=> ATMEL_US_USMODE_HWHS flag can be set for this platform ONLY IF the
CTS pin is not a GPIO.

So, the only case when ATMEL_US_USMODE_HWHS can be enabled is when
(atmel_use_fifo(port) &&
 !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))

Tested on all Atmel USART controller flavours:
AT91SAM9G35-CM (DMAC flavour), AT91SAM9G20-EK (PDC flavour),
SAMA5D2xplained (FIFO flavour).

* the list may not be exhaustive

Cc: <stable@vger.kernel.org> #4.4+ (beware, missing atmel_port variable)
Fixes: 1cf6e8fc83 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:10:48 -04:00
Greg Kroah-Hartman 463e2a2b89 serial: fsl_lpuart: remove build warning
commit 2a41bc2a2b ("tty: serial: fsl_lpuart: add polled console
functions") caused a build warning about an unused variable, so fix it.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Nicolae Rosia <nicolae_rosia@mentor.com>
Cc: Stefan Golinschi <stefan.golinschi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 02:47:35 -04:00