linux.git/drivers/tty/serial, branch v3.15

tty: serial: 8250_core.c Bug fix for Exar chips.

2014-05-03T22:13:05+00:00

The sleep function was updated to put the serial port to sleep only when necessary.
This appears to resolve the errant behavior of the driver as described in
Kernel Bug 61961 – "My Exar Corp. XR17C/D152 Dual PCI UART modem does not
work with 3.8.0".

Signed-off-by: Michael Welling 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial_core: fix uart PORT_UNKNOWN handling

2014-04-24T22:38:22+00:00

While porting a RS485 driver from 2.6.29 to 3.14, i noticed that the serial tty
driver could break it by using uart ports that it does not own :

1. uart_change_pm ist called during uart_open and calls the uart pm function
   without checking for PORT_UNKNOWN.
   The fix is to move uart_change_pm from uart_open to uart_port_startup.
2. The return code from the uart request_port call in uart_set_info is not
   handled properly, leading to the situation that the serial driver also
   thinks it owns the uart ports.
   This can triggered by doing following actions :

   setserial /dev/ttyS0 uart none    # release the uart ports
   modprobe lirc-serial              # or any other device that uses the uart
   setserial /dev/ttyS0 uart 16550   # gives no error and the uart tty driver
                                     # can use the ports as well

Signed-off-by: Thomas Pfaff 
Reviewed-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: samsung: Change barrier() to cpu_relax() in console output

2014-04-24T22:38:22+00:00

The two functions to write out to the console (one used in normal
console mode and one in polling console mode) were slightly different.
One used a barrier() in its loop and the other a cpu_relax().  The
barrier() really doesn't do anything since we're using rd_regl() to
read the port anyway.  Switch it to cpu_relax() to make things
consistent.

No known bugs / issues are fixed by this change--it just makes things
more consistent.

Signed-off-by: Doug Anderson 
Signed-off-by: Greg Kroah-Hartman

serial: samsung: don't check config for every character

2014-04-24T22:38:21+00:00

The s3c24xx_serial_console_putchar() is _only_ ever used by
s3c24xx_serial_console_write() and is called in a loop (indirectly
through uart_console_write()).  There's no reason to call
s3c24xx_port_configured() for every iteration through the loop.  Move
it outside the loop.

Signed-off-by: Doug Anderson 
Signed-off-by: Greg Kroah-Hartman

serial: samsung: Use the passed in "port", fixing kgdb w/ no console

2014-04-24T22:38:21+00:00

The two functions in the samsung serial driver used for writing
characters out to the port were inconsistent about whether they used
the passed in "port" or the global "cons_uart".  There was no reason
to use the global and the use of the global in
s3c24xx_serial_put_poll_char() caused a crash in the case where you
used the serial port for kgdboc but not for console.

Fix it so we used the passed in variable.

Note that this doesn't fix all problems with the samsung serial
driver.  Specifically:
* s3c24xx_serial_console_putchar() is still 99% identical to
  s3c24xx_serial_put_poll_char() (the function signature is different,
  but that's about it).  A future patch will make them slightly less
  identical and judging by other serial drivers we may need yet more
  differences eventually.
* The samsung serial driver still doesn't allow you to have more than
  one console port since it still uses the global cons_uart in
  s3c24xx_serial_console_write().

Signed-off-by: Doug Anderson 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Fix thread unsafe __dma_tx_complete function

2014-04-24T22:18:02+00:00

__dma_tx_complete is not protected against concurrent
call of serial8250_tx_dma. it can lead to circular tail
index corruption or parallel call of serial_tx_dma on the
same data portion.

This patch fixes this issue by holding the port lock.

Signed-off-by: Loic Poulain 
Reviewed-by: Heikki Krogerus 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

8250_core: Fix unwanted TX chars write

2014-04-24T22:18:02+00:00

On transmit-hold-register empty, serial8250_tx_chars
should be called only if we don't use DMA.
DMA has its own tx cycle.

Signed-off-by: Loic Poulain 
Reviewed-by: Heikki Krogerus 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

Revert "serial: 8250, disable "too much work" messages"

2014-04-17T16:33:19+00:00

This reverts commit f4f653e9875e573860e783fecbebde284a8626f5.

Jiri writes:
	No, please drop this one. We need a better solution as it turned
	out that some boxes need 16k loops and it will increase with new
	processors :(.

Cc: Jiri Slaby 
Cc: Martin Pluskal 
Cc: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: fix regression, causing an Oops on rmmod

2014-04-16T21:31:13+00:00

A recent commit ef2889f7ffee67f0aed49e854c72be63f1466759 "serial: pl011:
Move uart_register_driver call to device probe" introduced a regression,
causing the pl011 driver to Oops if more than 1 port have been probed. Fix
the Oops by only calling uart_unregister_driver() once after the last port
has been removed.

Signed-off-by: Guennadi Liakhovetski 
Signed-off-by: Greg Kroah-Hartman

serial: 8250, disable "too much work" messages

2014-04-16T21:20:34+00:00

The 8250 driver now reports many of these:
  serial8250: too much work for irq4
These messages turned out to be common these days with a use of
virtualization. I tried to increase the limit of processed characters
in commit e7328ae1848966181a7ac47e8ae6cddbd2cf55f3 (serial: 8250,
increase PASS_LIMIT) in 2011. It was raised from 256 to 512, but it is
still not enough, apparently.

So disable the warning unless somebody turns on DEBUG (or
DYNAMIC_DEBUG _and_ the message).

Signed-off-by: Jiri Slaby 
Reported-by: Martin Pluskal 
Reported-by: Takashi Iwai 
Tested-by: Takashi Iwai 
References: https://bugzilla.novell.com/show_bug.cgi?id=868394
Signed-off-by: Greg Kroah-Hartman