linux-stable.git/drivers/tty, branch v5.0.17

serial: ar933x_uart: Fix build failure with disabled console

2019-05-04T07:21:14+00:00

[ Upstream commit 72ff51d8dd262d1fef25baedc2ac35116435be47 ]

Andrey has reported on OpenWrt's bug tracking system[1], that he
currently can't use ar93xx_uart as pure serial UART without console
(CONFIG_SERIAL_8250_CONSOLE and CONFIG_SERIAL_AR933X_CONSOLE undefined),
because compilation ends with following error:

 ar933x_uart.c: In function 'ar933x_uart_console_write':
 ar933x_uart.c:550:14: error: 'struct uart_port' has no
                               member named 'sysrq'

So this patch moves all the code related to console handling behind
series of CONFIG_SERIAL_AR933X_CONSOLE ifdefs.

1. https://bugs.openwrt.org/index.php?do=details&task_id=2152

Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Andrey Batyiev 
Reported-by: Andrey Batyiev 
Tested-by: Andrey Batyiev 
Signed-off-by: Petr Štetiar 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin (Microsoft)

sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()

2019-05-04T07:21:14+00:00

[ Upstream commit ac0cdb3d990108df795b676cd0d0e65ac34b2273 ]

Add the missing uart_unregister_driver() and i2c_del_driver() before return
from sc16is7xx_init() in the error handling case.

Signed-off-by: Mao Wenan 
Reviewed-by: Vladimir Zapolskiy 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin (Microsoft)

vt: fix cursor when clearing the screen

2019-04-27T07:37:40+00:00

commit b2ecf00631362a83744e5ec249947620db5e240c upstream.

The patch a6dbe4427559 ("vt: perform safe console erase in the right
order") introduced a bug. The conditional do_update_region() was
replaced by a call to update_region() that does contain the conditional
already, but with unwanted extra side effects such as restoring the cursor
drawing.

In order to reproduce the bug:
- use framebuffer console with the AMDGPU driver
- type "links" to start the console www browser
- press 'q' and space to exit links

Now the cursor will be permanently visible in the center of the
screen. It will stay there until something overwrites it.

The bug goes away if we change update_region() back to the conditional
do_update_region().

[ nico: reworded changelog ]

Signed-off-by: Mikulas Patocka 
Reviewed-by: Nicolas Pitre 
Cc: stable@vger.kernel.org
Fixes: a6dbe4427559 ("vt: perform safe console erase in the right order")
Signed-off-by: Greg Kroah-Hartman

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

2019-04-27T07:37:40+00:00

commit ace965696da2611af759f0284e26342b7b6cec89 upstream.

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

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

2019-04-27T07:37:40+00:00

commit 6b87784b53592a90d21576be8eff688b56d93cce upstream.

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

tty: ldisc: add sysctl to prevent autoloading of ldiscs

2019-04-17T06:39:45+00:00

commit 7c0cca7c847e6e019d67b7d793efbbe3b947d004 upstream.

By default, the kernel will automatically load the module of any line
dicipline that is asked for.  As this sometimes isn't the safest thing
to do, provide a sysctl to disable this feature.

By default, we set this to 'y' as that is the historical way that Linux
has worked, and we do not want to break working systems.  But in the
future, perhaps this can default to 'n' to prevent this functionality.

Signed-off-by: Greg Kroah-Hartman 
Reviewed-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

tty: increase the default flip buffer limit to 2*640K

2019-04-05T20:34:46+00:00

[ Upstream commit 7ab57b76ebf632bf2231ccabe26bea33868118c6 ]

We increase the default limit for buffer memory allocation by a factor of
10 to 640K to prevent data loss when using fast serial interfaces.

For example when using RS485 without flow-control at speeds of 1Mbit/s
an upwards we've run into problems such as applications being too slow
to read out this buffer (on embedded devices based on imx53 or imx6).

If you want to write transmitted data to a slow SD card and thus have
realtime requirements, this limit can become a problem.

That shouldn't be the case and 640K buffers fix such problems for us.

This value is a maximum limit for allocation only. It has no effect
on systems that currently run fine. When transmission is slow enough
applications and hardware can keep up and increasing this limit
doesn't change anything.

It only _allows_ to allocate more than 2*64K in cases we currently fail to
allocate memory despite having some.

Signed-off-by: Manfred Schlaegl 
Signed-off-by: Martin Kepplinger 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_pxa: honor the port number from devicetree

2019-04-05T20:34:29+00:00

[ Upstream commit fe9ed6d2483fda55465f32924fb15bce0fac3fac ]

Like the other OF-enabled drivers, use the port number from the firmware if
the devicetree specifies an alias:

  aliases {
      ...
      serial2 = &uart2; /* Should be ttyS2 */
  }

This is how the deprecated pxa.c driver behaved, switching to 8250_pxa
messes up the numbering.

Signed-off-by: Lubomir Rintel 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

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

2019-04-03T04:27:34+00:00

commit 3ec8002951ea173e24b466df1ea98c56b7920e63 upstream.

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

serial: sh-sci: Fix setting SCSCR_TIE while transferring data

2019-04-03T04:27:33+00:00

commit 93bcefd4c6bad4c69dbc4edcd3fbf774b24d930d upstream.

We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted
(if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer,
re-enable the SCSCR_TIE bit, which was done at sci_start_tx().
This is unnecessary processing, wasting CPU operation if the data transmission length is large.
And further, transmit end, FIFO empty bits disabling have also been performed in the step above.

Signed-off-by: Hoan Nguyen An 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman