linux-stable.git/drivers/tty/serial, branch v4.4.130

Fix serial console on SNI RM400 machines

2018-04-13T17:50:17+00:00

[ Upstream commit e279e6d98e0cf2c2fe008b3c29042b92f0e17b1d ]

sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK
is disabled. Correct usage of clk API to make it work with/without it.

Fixes: 90efa75f7ab0 (serial: sccnxp: Using CLK API for getting UART clock)

Suggested-by: Russell King - ARM Linux 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix race condition causing garbage during shutdown

2018-04-13T17:50:07+00:00

[ Upstream commit 1cf4a7efdc71cab84c42cfea7200608711ea954f ]

If DMA is enabled and used, a burst of old data may be seen on the
serial console during "poweroff" or "reboot".  uart_flush_buffer()
clears the circular buffer, but sci_port.tx_dma_len is not reset.
This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE -
sci_port.tx_dma_len) bytes.

To fix this, add a .flush_buffer() callback that resets
sci_port.tx_dma_len.

Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race
condition (TX+DMA)").

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: omap: Disable DMA for console UART

2018-04-13T17:50:07+00:00

[ Upstream commit 84b40e3b57eef1417479c00490dd4c9f6e5ffdbc ]

Kernel always writes log messages to console via
serial8250_console_write()->serial8250_console_putchar() which directly
accesses UART_TX register _without_ using DMA.

But, if other processes like systemd using same UART port, then these
writes are handled by a different code flow using 8250_omap driver where
there is provision to use DMA.

It seems that it is possible that both DMA and CPU might simultaneously
put data to UART FIFO and lead to potential loss of data due to FIFO
overflow and weird data corruption. This happens when both kernel
console and userspace tries to write simultaneously to the same UART
port. Therefore, disable DMA on kernel console port to avoid potential
race between CPU and DMA.

Signed-off-by: Vignesh R 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Add Brainboxes UC-260 4 port serial device

2018-03-18T10:17:53+00:00

commit 9f2068f35729948bde84d87a40d135015911345d upstream.

Add PCI ids for two variants of Brainboxes UC-260 quad port
PCI serial cards.

Suggested-by: Andy Shevchenko 
Signed-off-by: Nikola Ciprich 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty/serial: atmel: add new version check for usart

2018-03-18T10:17:53+00:00

commit fd63a8903a2c40425a9811c3371dd4d0f42c0ad3 upstream.

On our at91sam9260 based board the usart0 and usart1 ports report
their versions (ATMEL_US_VERSION) as 0x10302. This version is not
included in the current checks in the driver.

Signed-off-by: Jonas Danielsson 
Acked-by: Richard Genoud 
Acked-by: Nicolas Ferre 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: prevent lockup on full TTY buffers

2018-03-18T10:17:53+00:00

commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream.

When the TTY buffers fill up to the configured maximum, a system lockup
occurs:

[  598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks:
[  598.825796]  0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1
[  598.832577]  (detected by 3, t=62517 jiffies, g=296, c=295, q=126)
[  598.838755] Task dump for CPU 0:
[  598.841977] swapper/0       R  running task        0     0      0 0x00000022
[  598.849023] Call trace:
[  598.851476]  __switch_to+0x98/0xb0
[  598.854870]            (null)

This can be prevented by doing a dummy read of the RX data register.

This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0;
reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms
as well.

Reported-by: Yoshihiro Shimoda 
Signed-off-by: Ulrich Hecht 
Reviewed-by: Geert Uytterhoeven 
Cc: stable 
Tested-by: Nguyen Viet Dung 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_mid: fix broken DMA dependency

2018-02-25T10:03:49+00:00

commit 0ff4230584320b2153752ba54e2e8edbd6addf2c upstream.

In order to enable HSU DMA PCI driver, the HSU DMA Engine
must be enabled. This add a check for that.

Reported-by: kbuild test robot 
Signed-off-by: Heikki Krogerus 
Signed-off-by: Greg Kroah-Hartman

serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS

2018-02-03T16:04:30+00:00

commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream.

The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS
lines, so only allow such wakeup method when the system actually has
RTS/CTS support.

Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD")
Signed-off-by: Fabio Estevam 
Reviewed-by: Martin Kaiser 
Acked-by: Fugang Duan 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Preserve DLD[7:4] for PORT_XR17V35X

2017-12-09T17:42:40+00:00

[ Upstream commit 0ab84da2e076948c49d36197ee7d254125c53eab ]

The upper four bits of the XR17V35x fractional divisor register (DLD)
control general chip function (RS-485 direction pin polarity, multidrop
mode, XON/XOFF parity check, and fast IR mode). Don't allow these bits
to be clobbered when setting the baudrate.

Signed-off-by: Aaron Sierra 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_fintek: Fix rs485 disablement on invalid ioctl()

2017-12-09T17:42:39+00:00

[ Upstream commit 3236a965486ba0c6043cf2c7b51943d8b382ae29 ]

This driver's ->rs485_config callback checks if SER_RS485_RTS_ON_SEND
and SER_RS485_RTS_AFTER_SEND have the same value.  If they do, it means
the user has passed in invalid data with the TIOCSRS485 ioctl()
since RTS must have a different polarity when sending and when not
sending.  In this case, rs485 mode is not enabled (the RS485_URA bit
is not set in the RS485 Enable Register) and this is supposed to be
signaled back to the user by clearing the SER_RS485_ENABLED bit in
struct serial_rs485 ... except a missing tilde character is preventing
that from happening.

Fixes: 28e3fb6c4dce ("serial: Add support for Fintek F81216A LPC to 4 UART")
Cc: Ricardo Ribalda Delgado 
Cc: "Ji-Ze Hong (Peter Hong)" 
Signed-off-by: Lukas Wunner 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman