linux-stable.git/drivers/tty/serial, branch v5.1.9

TTY: serial_core, add ->install

2019-06-11T10:19:23+00:00

commit 4cdd17ba1dff20ffc99fdbd2e6f0201fc7fe67df upstream.

We need to compute the uart state only on the first open. This is
usually what is done in the ->install hook. serial_core used to do this
in ->open on every open. So move it to ->install.

As a side effect, it ensures the state is set properly in the window
after tty_init_dev is called, but before uart_open. This fixes a bunch
of races between tty_open and flush_to_ldisc we were dealing with
recently.

One of such bugs was attempted to fix in commit fedb5760648a (serial:
fix race between flush_to_ldisc and tty_open), but it only took care of
a couple of functions (uart_start and uart_unthrottle).  I was able to
reproduce the crash on a SLE system, but in uart_write_room which is
also called from flush_to_ldisc via process_echoes. I was *unable* to
reproduce the bug locally. It is due to having this patch in my queue
since 2012!

 general protection fault: 0000 [#1] SMP KASAN PTI
 CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G             L 4.12.14-396-default #1 SLE15-SP1 (unreleased)
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014
 Workqueue: events_unbound flush_to_ldisc
 task: ffff8800427d8040 task.stack: ffff8800427f0000
 RIP: 0010:uart_write_room+0xc4/0x590
 RSP: 0018:ffff8800427f7088 EFLAGS: 00010202
 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 000000000000002f RSI: 00000000000000ee RDI: ffff88003888bd90
 RBP: ffffffffb9545850 R08: 0000000000000001 R09: 0000000000000400
 R10: ffff8800427d825c R11: 000000000000006e R12: 1ffff100084fee12
 R13: ffffc900004c5000 R14: ffff88003888bb28 R15: 0000000000000178
 FS:  0000000000000000(0000) GS:ffff880043300000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000561da0794148 CR3: 000000000ebf4000 CR4: 00000000000006e0
 Call Trace:
  tty_write_room+0x6d/0xc0
  __process_echoes+0x55/0x870
  n_tty_receive_buf_common+0x105e/0x26d0
  tty_ldisc_receive_buf+0xb7/0x1c0
  tty_port_default_receive_buf+0x107/0x180
  flush_to_ldisc+0x35d/0x5c0
...

0 in rbx means tty->driver_data is NULL in uart_write_room. 0x178 is
tried to be dereferenced (0x178 >> 3 is 0x2f in rdx) at
uart_write_room+0xc4. 0x178 is exactly (struct uart_state *)NULL->refcount
used in uart_port_lock from uart_write_room.

So revert the upstream commit here as my local patch should fix the
whole family.

Signed-off-by: Jiri Slaby 
Cc: Li RongQing 
Cc: Wang Li 
Cc: Zhang Yu 
Cc: Greg Kroah-Hartman 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: disable DMA for uart_console

2019-06-09T07:16:15+00:00

commit 099506cbbc79c0bd52b19cb6b930f256dabc3950 upstream.

As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for
console UART"), UART console lines use low-level PIO only access functions
which will conflict with use of the line when DMA is enabled, e.g. when
the console line is also used for systemd messages. So disable DMA
support for UART console lines.

Reported-by: Michael Rodin 
Link: https://patchwork.kernel.org/patch/10929511/
Tested-by: Eugeniu Rosca 
Reviewed-by: Simon Horman 
Reviewed-by: Wolfram Sang 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org
Signed-off-by: George G. Davis 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

tty: max310x: Fix external crystal register setup

2019-06-09T07:16:13+00:00

commit 5d24f455c182d5116dd5db8e1dc501115ecc9c2c upstream.

The datasheet states:

  Bit 4: ClockEnSet the ClockEn bit high to enable an external clocking
(crystal or clock generator at XIN). Set the ClockEn bit to 0 to disable
clocking
  Bit 1: CrystalEnSet the CrystalEn bit high to enable the crystal
oscillator. When using an external clock source at XIN, CrystalEn must
be set low.

The bit 4, MAX310X_CLKSRC_EXTCLK_BIT, should be set and was not.

This was required to make the MAX3107 with an external crystal on our
board able to send or receive data.

Signed-off-by: Joe Burmeister 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty: serial: msm_serial: Fix XON/XOFF

2019-06-09T07:16:13+00:00

commit 61c0e37950b88bad590056286c1d766b1f167f4e upstream.

When the tty layer requests the uart to throttle, the current code
executing in msm_serial will trigger "Bad mode in Error Handler" and
generate an invalid stack frame in pstore before rebooting (that is if
pstore is indeed configured: otherwise the user shall just notice a
reboot with no further information dumped to the console).

This patch replaces the PIO byte accessor with the word accessor
already used in PIO mode.

Fixes: 68252424a7c7 ("tty: serial: msm: Support big-endian CPUs")
Cc: stable@vger.kernel.org
Signed-off-by: Jorge Ramirez-Ortiz 
Reviewed-by: Bjorn Andersson 
Reviewed-by: Stephen Boyd 
Signed-off-by: Greg Kroah-Hartman

sc16is7xx: put err_spi and err_i2c into correct #ifdef

2019-04-19T12:09:23+00:00

err_spi is only called within SERIAL_SC16IS7XX_SPI
while err_i2c is called inside SERIAL_SC16IS7XX_I2C.
So we need to put err_spi and err_i2c into each #ifdef
accordingly.

This change fixes ("sc16is7xx: move label 'err_spi'
to correct section").

Signed-off-by: Guoqing Jiang 
Signed-off-by: Greg Kroah-Hartman

sc16is7xx: move label 'err_spi' to correct section

2019-04-16T13:24:38+00:00

err_spi is used when SERIAL_SC16IS7XX_SPI is enabled, so make
the label only available under SERIAL_SC16IS7XX_SPI option.
Otherwise, the below warning appears.

drivers/tty/serial/sc16is7xx.c:1523:1: warning: label ‘err_spi’ defined but not used [-Wunused-label]
 err_spi:
  ^~~~~~~

Signed-off-by: Guoqing Jiang 
Fixes: ac0cdb3d9901 ("sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix HSCIF RX sampling point adjustment

2019-04-16T13:24:38+00:00

The calculation of the sampling point has min() and max() exchanged.
Fix this by using the clamp() helper instead.

Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Ulrich Hecht 
Reviewed-by: Wolfram Sang 
Acked-by: Dirk Behme 
Cc: stable 
Reviewed-by: Simon Horman 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix HSCIF RX sampling point calculation

2019-04-16T13:24:38+00:00

There are several issues with the formula used for calculating the
deviation from the intended rate:
  1. While min_err and last_stop are signed, srr and baud are unsigned.
     Hence the signed values are promoted to unsigned, which will lead
     to a bogus value of deviation if min_err is negative,
  2. Srr is the register field value, which is one less than the actual
     sampling rate factor,
  3. The divisions do not use rounding.

Fix this by casting unsigned variables to int, adding one to srr, and
using a single DIV_ROUND_CLOSEST().

Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Mukesh Ojha 
Cc: stable 
Reviewed-by: Ulrich Hecht 
Signed-off-by: Greg Kroah-Hartman

Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc

2019-03-27T15:27:48+00:00

Echo "" to /sys/module/kgdboc/parameters/kgdboc will fail with "No such
device” error.

This is caused by function "configure_kgdboc" who init err to ENODEV
when the config is empty (legal input) the code go out with ENODEV
returned.

Fixes: 2dd453168643 ("kgdboc: Fix restrict error")
Signed-off-by: Wentao Wang 
Cc: stable 
Acked-by: Daniel Thompson 
Signed-off-by: Greg Kroah-Hartman

tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped

2019-03-27T15:27:48+00:00

In half-duplex operation, RX should be started after TX completes.

If DMA is used, there is a case when the DMA transfer completes but the
TX FIFO is not emptied, so the RX cannot be restarted just yet.

Use a boolean variable to store this state and rearm TX interrupt mask
to be signaled again that the transfer finished. In interrupt transmit
handler this variable is used to start RX. A warning message is generated
if RX is activated before TX fifo is cleared.

Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable
RX after TX is done")
Signed-off-by: Razvan Stefanescu 
Acked-by: Richard Genoud 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman