linux-stable.git/drivers/tty, branch v3.0.69

fb: Yet another band-aid for fixing lockdep mess

2013-02-28T14:32:27+00:00

commit e93a9a868792ad71cdd09d75e5a02d8067473c4e upstream.

I've still got lockdep warnings even after Alan's patch, and it seems that
yet more band aids are required to paper over similar paths for
unbind_con_driver() and unregister_con_driver().  After this hack, lockdep
warnings are finally gone.

Signed-off-by: Takashi Iwai 
Cc: Alan Cox 
Cc: Florian Tobias Schandinat 
Cc: Jiri Kosina 
Tested-by: Sedat Dilek 
Signed-off-by: Andrew Morton 
Signed-off-by: Dave Airlie 
Signed-off-by: Greg Kroah-Hartman

fb: rework locking to fix lock ordering on takeover

2013-02-28T14:32:27+00:00

commit 50e244cc793d511b86adea24972f3a7264cae114 upstream.

Adjust the console layer to allow a take over call where the caller
already holds the locks.  Make the fb layer lock in order.

This is partly a band aid, the fb layer is terminally confused about the
locking rules it uses for its notifiers it seems.

[akpm@linux-foundation.org: remove stray non-ascii char, tidy comment]
[akpm@linux-foundation.org: export do_take_over_console()]
[airlied: cleanup another non-ascii char]
Signed-off-by: Alan Cox 
Cc: Florian Tobias Schandinat 
Cc: Stephen Rothwell 
Cc: Jiri Kosina 
Tested-by: Sedat Dilek 
Reviewed-by: Daniel Vetter 
Signed-off-by: Andrew Morton 
Signed-off-by: Dave Airlie 
Signed-off-by: Greg Kroah-Hartman

tty: set_termios/set_termiox should not return -EINTR

2013-02-28T14:32:24+00:00

commit 183d95cdd834381c594d3aa801c1f9f9c0c54fa9 upstream.

See https://bugzilla.redhat.com/show_bug.cgi?id=904907
read command causes bash to abort with double free or corruption (out).

A simple test-case from Roman:

	// Compile the reproducer and send sigchld ti that process.
	// EINTR occurs even if SA_RESTART flag is set.

	void handler(int sig)
	{
	}

	main()
	{
	  struct sigaction act;
	  act.sa_handler = handler;
	  act.sa_flags = SA_RESTART;
	  sigaction (SIGCHLD, &act, 0);
	  struct termio ttp;
	  ioctl(0, TCGETA, &ttp);
	  while(1)
	  {
	    if (ioctl(0, TCSETAW, ttp) < 0)
	      {
		if (errno == EINTR)
		{
		  fprintf(stderr, "BUG!"); return(1);
		}
	      }
	  }
	}

Change set_termios/set_termiox to return -ERESTARTSYS to fix this
particular problem.

I didn't dare to change other EINTR's in drivers/tty/, but they look
equally wrong.

Reported-by: Roman Rakus 
Reported-by: Lingzhu Xiang 
Signed-off-by: Oleg Nesterov 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

serial: 8250, increase PASS_LIMIT

2013-01-28T04:46:29+00:00

commit e7328ae1848966181a7ac47e8ae6cddbd2cf55f3 upstream.

With virtual machines like qemu, it's pretty common to see "too much
work for irq4" messages nowadays. This happens when a bunch of output
is printed on the emulated serial console. This is caused by too low
PASS_LIMIT. When ISR loops more than the limit, it spits the message.

I've been using a kernel with doubled the limit and I couldn't see no
problems. Maybe it's time to get rid of the message now?

Signed-off-by: Jiri Slaby 
Cc: Alan Cox 
Cc: Ram Gupta 
Signed-off-by: Greg Kroah-Hartman

serial:ifx6x60:Delete SPI timer when shut down port

2013-01-21T19:45:00+00:00

commit 014b9b4ce84281ccb3d723c792bed19815f3571a upstream.

When shut down SPI port, it's possible that MRDY has been asserted and a SPI
timer was activated waiting for SRDY assert, in the case, it needs to delete
this timer.

Signed-off-by: Chen Jun 
Signed-off-by: channing 
Signed-off-by: Greg Kroah-Hartman

n_gsm: memory leak in uplink error path

2012-10-07T15:27:26+00:00

commit 88ed2a60610974443335c924d7cb8e5dcf9dbdc1 upstream.

Uplink (TX) network data will go through gsm_dlci_data_output_framed
there is a bug where if memory allocation fails, the skb which
has already been pulled off the list will be lost.

In addition TX skbs were being processed in LIFO order

Fixed the memory leak, and changed to FIFO order processing

Signed-off-by: Russ Gorby 
Tested-by: Kappel, LaurentX 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

n_gsm: added interlocking for gsm_data_lock for certain code paths

2012-10-07T15:27:25+00:00

commit 5e44708f75b0f8712da715d6babb0c21089b2317 upstream.

There were some locking holes in the management of the MUX's
message queue for 2 code paths:
1) gsmld_write_wakeup
2) receipt of CMD_FCON flow-control message
In both cases gsm_data_kick is called w/o locking so it can collide
with other other instances of gsm_data_kick (pulling messages tx_tail)
or potentially other instances of __gsm_data_queu (adding messages to tx_head)

Changed to take the tx_lock in these 2 cases

Signed-off-by: Russ Gorby 
Tested-by: Yin, Fengwei 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: set correct baud_base for EXSYS EX-41092 Dual 16950

2012-10-07T15:27:25+00:00

commit 26e8220adb0aec43b7acafa0f1431760eee28522 upstream.

Apparently the same card model has two IDs, so this patch
complements the commit 39aced68d664291db3324d0fcf0985ab5626aac2
adding the missing one.

Signed-off-by: Flavio Leitner 
Signed-off-by: Greg Kroah-Hartman

serial: pl011: handle corruption at high clock speeds

2012-10-07T15:27:25+00:00

commit c5dd553b9fd069892c9e2de734f4f604e280fa7a upstream.

This works around a few glitches in the ST version of the PL011
serial driver when using very high baud rates, as we do in the
Ux500: 3, 3.25, 4 and 4.05 Mbps.

Problem Observed/rootcause:

When using high baud-rates, and the baudrate*8 is getting close to
the provided clock frequency (so a division factor close to 1), when
using bursts of characters (so they are abutted), then it seems as if
there is not enough time to detect the beginning of the start-bit which
is a timing reference for the entire character, and thus the sampling
moment of character bits is moving towards the end of each bit, instead
of the middle.

Fix:
Increase slightly the RX baud rate of the UART above the theoretical
baudrate by 5%. This will definitely give more margin time to the
UART_RX to correctly sample the data at the middle of the bit period.

Also fix the ages old copy-paste error in the very stressed comment,
it's referencing the registers used in the PL010 driver rather than
the PL011 ones.

Signed-off-by: Guillaume Jaunet 
Signed-off-by: Christophe Arnal 
Signed-off-by: Matthias Locher 
Signed-off-by: Rajanikanth HV 
Cc: Bibek Basu 
Cc: Par-Gunnar Hjalmdahl 
Signed-off-by: Linus Walleij 
Signed-off-by: Greg Kroah-Hartman

Remove BUG_ON from n_tty_read()

2012-10-07T15:27:24+00:00

commit e9490e93c1978b6669f3e993caa3189be13ce459 upstream.

Change the BUG_ON to WARN_ON and return in case of tty->read_buf==NULL. We want to track a
couple of long standing reports of this but at the same time we can avoid killing the box.

Signed-off-by: Stanislav Kozina 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman