4745 Commits

Author SHA1 Message Date
Nicolas Ferre
497e1e16f4 tty/serial: atmel: fix TX path in atmel_console_write()
A side effect of 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA
from transmitting in stop_tx") is that the console can be called with
TX path disabled. Then the system would hang trying to push charecters
out in atmel_console_putchar().

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Fixes: 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting
in stop_tx")
Cc: stable <stable@vger.kernel.org>	#4.4+
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:20 +02:00
Richard Genoud
31ca2c63fd tty/serial: atmel: fix race condition (TX+DMA)
If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).

Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:19 +02:00
Uwe Kleine-König
a6040bc610 serial: mxs-auart: Fix baudrate calculation
The reference manual for the i.MX28 recommends to calculate the divisor
as

	divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer

, so let's do this. For a typical setup of UARTCLK = 24 MHz and baud
rate = 115200 this changes the divisor from 6666 to 6667 and so the
actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to
115194.240 Bd (error ≅ 0.005 %).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:19 +02:00
Stefan Agner
abf1e0a980 tty: serial: fsl_lpuart: lock port on console write
The console write code is not entirely race free (e.g. the operations
to disabling the UART interrupts are not atomic) hence locking is
required. This has been become apparent with the PREEMPT RT patchset
applied: With the fully preemptible kernel configuration the system
often ended up in a freeze already at startup.

Disable interrupts and lock using read_lock_irqsave. Try to lock in
the sysrq/oops case, but don't bother if locking fails.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Tobias Klauser
4d9d7d896d serial: altera_uart: add earlycon support
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_uart.

Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Tim Gardner
a4199f5eb8 tty: Disable default console blanking interval
BugLink: http://bugs.launchpad.net/bugs/869017

Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).

Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Vignesh R
b2c663d155 serial: 8250: 8250_core: Fix irq name for 8250 serial IRQ
Using dev_name() as IRQ name during request_irq() might be misleading in
case of serial over PCI. Therefore identify serial port IRQ using
uart_port's name field. This will help mapping IRQs to appropriate
ttySN(where N is the serial port index) instances.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Vignesh R
f7048b1590 tty: serial_core: Add name field to uart_port struct
Introduce a field to store name of uart_port that can be used to easily
identify UART port instances on a system that has more than one UART
instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N
is number that particular UART instance.
This field will be useful when printing debug info for a particular port
or in register IRQs with unique IRQ name. Port name is populated during
uart_add_one_port().

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Jan Kiszka
7cd3e9dbdd serial: 8250_lpss: Unconditionally set PCI master for Quark
MSI needs it as well.

Should have no practical impact, though, as DMA is always available on
the Quark. But given the few users of pci_alloc_irq_vectors so far, this
incorrect pattern may spread otherwise.

Fixes: 3f3a46951e02 ("serial: 8250_lpss: set PCI master only for private DMA")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:36:54 +02:00
Geert Uytterhoeven
cfa6eb2391 serial: sh-sci: Fix (AUTO)RTS in sci_init_pins()
If a UART has dedicated RTS/CTS pins, and hardware control flow is
disabled (or AUTORTS is not yet effective), changing any serial port
configuration deasserts RTS, as .set_termios() calls sci_init_pins().

To fix this, consider the current (AUTO)RTS state when (re)initializing
the pins.  Note that for SCIFA/SCIFB, AUTORTS needs explicit
configuration of the RTS# pin function, while (H)SCIF handles this
automatically.

Fixes: d2b9775d795ec05f ("serial: sh-sci: Correct pin initialization on (H)SCIF")
Fixes: e9d7a45a03991349 ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:06 +02:00
Geert Uytterhoeven
5f76895e4c serial: sh-sci: Fix late enablement of AUTORTS
When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised.  However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.

To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).

Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc253854cf ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Geert Uytterhoeven
e37f712f76 serial: sh-sci: Fix hang in sci_reset()
When the .set_termios() callback resets the UART, it first waits (busy
loops) until all characters in the transmit FIFO have been transmitted,
to prevent a port configuration change from impacting these characters.

However, if the UART has dedicated RTS/CTS hardware flow control
enabled, these characters may have been stuck in the FIFO due to CTS not
being asserted by the remote side.

  - When a new user opens the port, .set_termios() is called while
    transmission is still disabled, leading to an infinite loop:

	NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!

  - When an active user changes port configuration without waiting for
    the draining of the transmit FIFO, this may also block indefinitely,
    until CTS is asserted by the remote side.

This has been observed with SCIFA (on r8a7740/armadillo), and SCIFB and
HSCIF (on r8a7791/koelsch).

To fix this, remove the code that waits for the draining of the transmit
FIFO.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Lee Jones
b5090cb46e serial: st-asc: Change default baudrate from 9600 to 115200
9600 is old school.

Most applications use 115200 as the default baud these days.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Lionel Debieve
ef49ffd8b5 tty: serial: st-asc: Make the locking RT aware
The lock is a sleeping lock and local_irq_save() is not the
standard implementation now. Working for both -RT and non
RT.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Denis Kirjanov
19fa6e601b tty/hvc_console: fix console lock ordering with spinlock
hvc_remove() takes a spin lock first then acquires the console
semaphore. This situation can easily lead to a deadlock scenario
where we call scheduler with spin lock held.

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
93857edd98 tty: reset termios state on device registration
Free any saved termios data when registering a tty device so that the
termios state is reset when reusing a minor number.

This is useful for hot-pluggable buses such as USB where it does not
make much sense to reuse saved termios data from an unrelated device
when a new device is later plugged in.

This specifically avoids a situation where the new device does not have
the carrier-detect signal wired, but the saved termios state has CLOCAL
cleared, effectively preventing the port from being opened in blocking
mode as noted by Jan Kundrát <jan.kundrat@cesnet.cz>.

Note that clearing the saved data at deregistration would not work as
the device could still be open.

Also note that the termios data is not reset for drivers with
TTY_DRIVER_DYNAMIC_ALLOC set (e.g. legacy pty) as their character device
is registered at driver registration and could theoretically already
have been opened (and pty termios state is never saved anyway).

Reported-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
16b00ae82d tty: drop obsolete termios_locked comments
Drop comments about tty-driver termios_locked structures, which have
been outdated since commit fe6e29fdb1a7 ("tty: simplify ktermios
allocation").

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
6a7e6f78c2 tty: close race between device register and open
The tty class device is currently not registered until after the
character device has been registered thereby leaving a small window
were a racing open could end up with a NULL tty->dev pointer due to the
class-device lookup failing in alloc_tty_struct.

Close this race by registering the class device before the character
device while making sure to defer the user-space uevent notification
until after the character device has been registered.

Note that some tty drivers expect a valid tty->dev and would misbehave
or crash otherwise. Some line disciplines also currently dereference the
class device unconditionally despite the fact that not every tty is
guaranteed to have one (Unix98 pty), but this is being fixed separately.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Greg Kroah-Hartman
53c1cf4281 Merge 4.11-rc4 into tty-next
We want the tty/serial fixes in here to handle bugfixes and merge
issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-29 08:58:53 +02:00
Greg Kroah-Hartman
896d81fefe Revert "tty: Fix ldisc crash on reopened tty"
This reverts commit 71472fa9c52b1da27663c275d416d8654b905f05.  It caused
merge issues, and Dmitry found some review issues.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-29 07:50:49 +02:00
Ingo Molnar
658b299580 sched/headers: Remove duplicate #include <linux/sched/debug.h> line
Vito Caputo reported that the sched.h split-up series
introduced a duplicate #include <linux/sched/debug.h> line
in drivers/tty/vt/keyboard.c.

Remove it.

Reported-by: Vito Caputo <vcaputo@pengaru.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-28 09:56:03 +02:00
Linus Torvalds
f1638fc65e TTY/Serial driver fixes for 4.11-rc4
Here are some tty and serial driver fixes for 4.11-rc4.  One of these
 fix a long-standing issue in the ldisc code that was found by Dmitry
 Vyukov with his great fuzzing work.  The other fixes resolve other
 reported issues, and there is one revert of a patch in 4.11-rc1 that
 wasn't correct.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some tty and serial driver fixes for 4.11-rc4.

  One of these fix a long-standing issue in the ldisc code that was
  found by Dmitry Vyukov with his great fuzzing work. The other fixes
  resolve other reported issues, and there is one revert of a patch in
  4.11-rc1 that wasn't correct.

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

* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix data race in tty_ldisc_ref_wait()
  tty: don't panic on OOM in tty_set_ldisc()
  Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
  tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
  serial: 8250_dw: Fix breakage when HAVE_CLK=n
  serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
2017-03-26 11:03:42 -07:00
Rob Herring
0634c29589 of: Add function for generating a DT modalias with a newline
The modalias sysfs attr is lacking a newline for DT aliases on platform
devices. The macio and ibmebus correctly add the newline, but open code it.
Introduce a new function, of_device_modalias(), that fills the buffer with
the modalias including the newline and update users of the old
of_device_get_modalias function.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22 14:56:13 -05:00
Linus Torvalds
4719177780 GPIO fixes for the v4.11 series:
- Set the parent on the Altera A10SR driver, also fix
   high level IRQs.
 
 - Fix error path on the mockup driver.
 
 - Compilation noise about unused functions fixed.
 
 - Fix missed interrupts on the MCP23S08 expander, this is also
   tagged for stable.
 
 - Retire the interrim helpers devm_get_gpiod_from_child() used
   to smoothen merging in the merge window.
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Merge tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO fixes from Linus Walleij:
 "Here is the first set of GPIO fixes for 4.11. It was delayed a bit
  beacuse I was chicken when linux-next was not rotating last week.

  This hits the ST serial driver in drivers/tty/serial and that has an
  ACK from Greg, he suggested to keep the old GPIO fwnode API around to
  smoothen things in the merge Windod and those have now served their
  purpose so we take them out and convert the last driver to the new
  API.

  Apart from that it's fixes as usual.

  Summary:

   - set the parent on the Altera A10SR driver, also fix high level
     IRQs.

   - fix error path on the mockup driver.

   - compilation noise about unused functions fixed.

   - fix missed interrupts on the MCP23S08 expander, this is also tagged
     for stable.

   - retire the interrim helpers devm_get_gpiod_from_child() used to
     smoothen merging in the merge window"

* tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio:mcp23s08 Fixed missing interrupts
  serial: st-asc: Use new GPIOD API to obtain RTS pin
  gpio: altera: Use handle_level_irq when configured as a level_high
  gpio: xgene: mark PM functions as __maybe_unused
  gpio: mockup: return -EFAULT if copy_from_user() fails
  gpio: altera-a10sr: Set gpio_chip parent property
2017-03-21 13:01:53 -07:00
Philipp Zabel
acbdad8dd1 serial: 8250_dw: simplify optional reset handling
As of commit bb475230b8e5 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.

This allows to return errors from devm_reset_control_get_optional and to
call reset_control_(de)assert unconditionally.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:12 +09:00
Jiri Slaby
22077b091a tty: serial_core, remove state checks in uart_poll*
Coverity complains about uart_state checks in polling functions. And it
is indeed correct. We do something like this:
	struct uart_state *state = drv->state + line;
	if (!state)
		return;

Adding 'line' to drv->state would move the potential NULL pointer to
something near NULL and the check is useless. Even if we checked pure
drv->state, nothing guarantees it is not freed and NULLed after the
check. So if the only user of this interface (kgdboc) needs to assure
something, this is neither the correct thing, nor place to do so.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:11 +09:00
Lukas Redlinger
fab8a02b73 serial: 8250_fintek: Enable high speed mode on Fintek F81866
Fintek F81866 supports baud rates higher than 115200 but needs to raise
it's clock speed from 1.84 to 14.76 MHz.
This is eight times faster, so gives 921600 as resulting baud_base.

F81866 clock register 0xf2:
    Bit 7-2    reserved
    Bit 1-0    00: 1.8432MHz
               01: 18.432MHz
               10: 24MHz
               11: 14.769MHz

Signed-off-by: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:11 +09:00
Peter Hurley
71472fa9c5 tty: Fix ldisc crash on reopened tty
If the tty has been hungup, the ldisc instance may have been destroyed.
Continued input to the tty will be ignored as long as the ldisc instance
is not visible to the flush_to_ldisc kworker. However, when the tty
is reopened and a new ldisc instance is created, the flush_to_ldisc
kworker can obtain an ldisc reference before the new ldisc is
completely initialized. This will likely crash:

 BUG: unable to handle kernel paging request at 0000000000002260
 IP: [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
 PGD 2ab581067 PUD 290c11067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP
 Modules linked in: nls_iso8859_1 ip6table_filter [.....]
 CPU: 2 PID: 103 Comm: kworker/u16:1 Not tainted 4.6.0-rc7+wip-xeon+debug #rc7+wip
 Hardware name: Dell Inc. Precision WorkStation T5400  /0RW203, BIOS A11 04/30/2012
 Workqueue: events_unbound flush_to_ldisc
 task: ffff8802ad16d100 ti: ffff8802ad31c000 task.ti: ffff8802ad31c000
 RIP: 0010:[<ffffffff8152dc5d>]  [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
 RSP: 0018:ffff8802ad31fc70  EFLAGS: 00010296
 RAX: 0000000000000000 RBX: ffff8802aaddd800 RCX: 0000000000000001
 RDX: 00000000ffffffff RSI: ffffffff810db48f RDI: 0000000000000246
 RBP: ffff8802ad31fd08 R08: 0000000000000000 R09: 0000000000000001
 R10: ffff8802aadddb28 R11: 0000000000000001 R12: ffff8800ba6da808
 R13: ffff8802ad18be80 R14: ffff8800ba6da858 R15: ffff8800ba6da800
 FS:  0000000000000000(0000) GS:ffff8802b0a00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000002260 CR3: 000000028ee5d000 CR4: 00000000000006e0
 Stack:
  ffffffff81531219 ffff8802aadddab8 ffff8802aadddde0 ffff8802aadddd78
  ffffffff00000001 ffff8800ba6da858 ffff8800ba6da860 ffff8802ad31fd30
  ffffffff81885f78 ffffffff81531219 0000000000000000 0000000200000000
 Call Trace:
  [<ffffffff81531219>] ? flush_to_ldisc+0x49/0xd0
  [<ffffffff81885f78>] ? mutex_lock_nested+0x2c8/0x430
  [<ffffffff81531219>] ? flush_to_ldisc+0x49/0xd0
  [<ffffffff8152e784>] n_tty_receive_buf2+0x14/0x20
  [<ffffffff81530cb2>] tty_ldisc_receive_buf+0x22/0x50
  [<ffffffff8153128e>] flush_to_ldisc+0xbe/0xd0
  [<ffffffff810a0ebd>] process_one_work+0x1ed/0x6e0
  [<ffffffff810a0e3f>] ? process_one_work+0x16f/0x6e0
  [<ffffffff810a13fe>] worker_thread+0x4e/0x490
  [<ffffffff810a13b0>] ? process_one_work+0x6e0/0x6e0
  [<ffffffff810a7ef2>] kthread+0xf2/0x110
  [<ffffffff810ae68c>] ? preempt_count_sub+0x4c/0x80
  [<ffffffff8188ab52>] ret_from_fork+0x22/0x50
  [<ffffffff810a7e00>] ? kthread_create_on_node+0x220/0x220
 Code: ff ff e8 27 a0 35 00 48 8d 83 78 05 00 00 c7 45 c0 00 00 00 00 48 89 45 80 48
       8d 83 e0 05 00 00 48 89 85 78 ff ff ff 48 8b 45 b8 <48> 8b b8 60 22 00 00 48
       8b 30 89 f8 8b 8b 88 04 00 00 29 f0 8d
 RIP  [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
  RSP <ffff8802ad31fc70>
 CR2: 0000000000002260

Ensure the kworker cannot obtain the ldisc reference until the new ldisc
is completely initialized.

Fixes: 892d1fa7eaae ("tty: Destroy ldisc instance on hangup")
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:16:09 +09:00
Wang YanQing
77dae61344 tty: pty: Fix ldisc flush after userspace become aware of the data already
While using emacs, cat or others' commands in konsole with recent
kernels, I have met many times that CTRL-C freeze konsole. After
konsole freeze I can't type anything, then I have to open a new one,
it is very annoying.

See bug report:
https://bugs.kde.org/show_bug.cgi?id=175283

The platform in that bug report is Solaris, but now the pty in linux
has the same problem or the same behavior as Solaris :)

It has high possibility to trigger the problem follow steps below:
Note: In my test, BigFile is a text file whose size is bigger than 1G
1:open konsole
1:cat BigFile
2:CTRL-C

After some digging, I find out the reason is that commit 1d1d14da12e7
("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer.

Thread A                                 Thread B
--------                                 --------
1:n_tty_poll return POLLIN
                                         2:CTRL-C trigger pty_flush_buffer
                                             tty_buffer_flush
                                               n_tty_flush_buffer
3:attempt to check count of chars:
  ioctl(fd, TIOCINQ, &available)
  available is equal to 0

4:read(fd, buffer, avaiable)
  return 0

5:konsole close fd

Yes, I know we could use the same patch included in the BUG report as
a workaround for linux platform too. But I think the data in ldisc is
belong to application of another side, we shouldn't clear it when we
want to flush write buffer of this side in pty_flush_buffer. So I think
it is better to disable ldisc flush in pty_flush_buffer, because its new
hehavior bring no benefit except that it mess up the behavior between
POLLIN, and TIOCINQ or FIONREAD.

Also I find no flush_buffer function in others' tty driver has the
same behavior as current pty_flush_buffer.

Fixes: 1d1d14da12e7 ("pty: Fix buffer flush deadlock")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:16:09 +09:00
Sam Povilus
b44b96a060 uartlite: Adding a kernel parameter for the number of uartlites
The number of uartlites should be set by a kernel parameter instead of
using a #define. This allows the user to set the number of uartlites
using only kconfig and not modifying kernel source.

The uartlite is used by FPGAs that support a basically unlimited number
of uarts so limiting it at 16 dosn't make sense as users might need more
than that.

Signed-off-by: Sam Povilus <kernel.development@povil.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:30 +09:00
Shubhrajyoti Datta
81e33b51ed serial: xuartps: Cleanup the clock enable
The core handles the clocking now. Remove the clock disable in
suspend. In resume we enable the clocks and disable after register
write.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Tobias Klauser
0dcc0542a0 serial: altera_jtaguart: add earlycon support
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_jtaguart
(and altera_uart for that matter).

Add earlycon support to altera_jtaguart so that other archs may use it. Also,
this will allow the early printk implementation in arch/nios2 to eventually be
removed in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Tobias Klauser
47baf1ad81 tty: n_gsm: Use net_device_stats from struct net_device
Instead of using a private copy of struct net_device_stats in struct
gsm_mux_net, use stats from struct net_device. Also remove
the now unnecessary .ndo_get_stats function.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Joe Perches
d437fa9109 drivers/tty: Convert remaining uses of pr_warning to pr_warn
To enable eventual removal of pr_warning

This makes pr_warn use consistent for drivers/tty

Prior to this patch, there were 2 uses of pr_warning and
23 uses of pr_warn in drivers/tty

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Dmitry Vyukov
a4a3e06114 tty: fix data race in tty_ldisc_ref_wait()
tty_ldisc_ref_wait() checks tty->ldisc under tty->ldisc_sem.
But if ldisc==NULL it releases them sem and reloads
tty->ldisc without holding the sem. This is wrong and
can lead to returning non-NULL ldisc without protection.

Don't reload tty->ldisc second time.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:07:10 +09:00
Dmitry Vyukov
5362544beb tty: don't panic on OOM in tty_set_ldisc()
If tty_ldisc_open() fails in tty_set_ldisc(), it tries to go back
to the old discipline or N_TTY. But that can fail as well, in such
case it panics. This is not a graceful way to handle OOM.

Leave ldisc==NULL if all attempts fail instead.
Also use existing tty_ldisc_reinit() helper function instead of
tty_ldisc_restore(). Also don't WARN/BUG in tty_ldisc_reinit()
if N_TTY fails, which would have the same net effect of bringing
kernel down on OOM. Instead print a single line message about
what has happened.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:07:10 +09:00
Aleksey Makarov
b767ad726c Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80ba98a0c9b4de88850260e9fbdcc98360b.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:04:06 +09:00
Lee Jones
0043c1dfbe serial: st-asc: Use new GPIOD API to obtain RTS pin
The commits mentioned below adapt the GPIO API to allow more information
to be passed directly through devm_get_gpiod_from_child() in the first
instance.  This facilitates the removal of subsequent calls, such as
gpiod_direction_output().  This patch firstly moves to utilise the new
API and secondly removes the now superfluous call do set the direction.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Also drop the header file dummies that only this driver was using]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-14 10:36:41 +01:00
Shubhrajyoti Datta
d62100f1aa serial: xilinx_uartps: Add pm runtime support
Adds pm runtime support to xilinx uart ps.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Vignesh R
f48180a70e serial: 8250: 8250_core: Use dev_name() during request_irq()
Passing "serial" as name during request_irq() results in all serial port
irqs have same name. This does not help much to easily identify which
irq belongs to which serial port instance. Therefore pass dev_name()
during request_irq() so that better identifiable name is listed for
serial ports in cat /proc/interrupts output.

Output of cat /proc/interrupts
Before this patch:
 26:        689          0     GICv2 309 Edge      serial
After this patch:
 26:        696          0     GICv2 309 Edge      2530c00.serial

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Elena Reshetova
22a33651a5 drivers: convert sbd_duart.map_guard from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Richard Genoud
8961df8950 tty/serial: atmel: move atmel_serial header into driver directory
atmel_serial.h is only used by atmel_serial.c, so there's no need for
it to lie in include/linux.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Andy Shevchenko
2b57b7ff9d serial: 8250_exar: Fix spelling of "driver"
Fix typo in "Dricer".

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Alexandre Belloni
488ae82d97 tty/serial: atmel: remove cache when unnecessary
struct cache is only used in suspend/resume. Exclude it when PM is not
selected.

Suggested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Alexandre Belloni
432f974801 tty/serial: atmel: increase ATMEL_MAX_UART
The samx7 family uses the same UART/USART IP as the at91/sama5 families but
has 8 of those.

Suggested-by: Szemző András <sza@esh.hu>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Takatoshi Akiyama
3c9101766b serial: sh-sci: Fix panic when serial console and DMA are enabled
This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.

* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
  and used in interrupt.

If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().

Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Aleksey Makarov
713b93f1b8 Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80ba98a0c9b4de88850260e9fbdcc98360b.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
James Hogan
b15bfbe642 serial: 8250_dw: Fix breakage when HAVE_CLK=n
Commit 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be
used") recently broke the 8250_dw driver on platforms which don't select
HAVE_CLK, as dw8250_set_termios() gets confused by the behaviour of the
fallback HAVE_CLK=n clock API in linux/clk.h which pretends everything
is fine but returns (valid) NULL clocks and 0 HZ clock rates.

That 0 rate is written into the uartclk resulting in a crash at boot,
e.g. on Cavium Octeon III based UTM-8 we get something like this:

1180000000800.serial: ttyS0 at MMIO 0x1180000000800 (irq = 41, base_baud = 25000000) is a OCTEON
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1 at drivers/tty/serial/serial_core.c:441 uart_get_baud_rate+0xfc/0x1f0
...
Call Trace:
...
[<ffffffff8149c2e4>] uart_get_baud_rate+0xfc/0x1f0
[<ffffffff814a5098>] serial8250_do_set_termios+0xb0/0x440
[<ffffffff8149c710>] uart_set_options+0xe8/0x190
[<ffffffff814a6cdc>] serial8250_console_setup+0x84/0x158
[<ffffffff814a11ec>] univ8250_console_setup+0x54/0x70
[<ffffffff811901a0>] register_console+0x1c8/0x418
[<ffffffff8149f004>] uart_add_one_port+0x434/0x4b0
[<ffffffff814a1af8>] serial8250_register_8250_port+0x2d8/0x440
[<ffffffff814aa620>] dw8250_probe+0x388/0x5e8
...

The clock API is defined such that NULL is a valid clock handle so it
wouldn't be right to check explicitly for NULL. Instead treat a
clk_round_rate() return value of 0 as an error which prevents uartclk
being overwritten.

Fixes: 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-serial@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jason Uy <jason.uy@broadcom.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:48:11 +08:00
Heiko Stuebner
09498087f9 serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
clk_round_rate returns a signed long and may possibly return errors
in it, for example if there is no possible rate.

Till now dw8250_set_termios ignored any error, the signednes and would
just use the value as input to clk_set_rate. This of course falls apart
if there is an actual error, so check for errors and only try to set
a rate if the value is actually valid.

This turned up on some Rockchip platforms after commit
6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used")
enabled set_termios callback in all cases, not only ACPI.

Fixes: 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:48:11 +08:00
Krzysztof Kozlowski
f98c7bce57 serial: samsung: Continue to work if DMA request fails
If DMA is not available (even when configured in DeviceTree), the driver
will fail the startup procedure thus making serial console not
available.

For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210):
    [    1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000
    ...
    [   11.435732] samsung-uart 13800000.serial: DMA request failed
    [   72.963893] samsung-uart 13800000.serial: DMA request failed
    [   73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000

DMA is not necessary for serial to work, so continue with UART startup
after emitting a warning.

Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-07 19:58:37 +01:00