linux-toradex.git/drivers/tty/n_tty.c, branch v3.7

Remove BUG_ON from n_tty_read()

2012-08-16T18:53:14+00:00

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 
Cc: Horses 
Signed-off-by: Greg Kroah-Hartman

n_tty: Don't lose characters when PARMRK is enabled

2012-08-10T20:14:54+00:00

When PARMRK is set and large transfers of characters that will get
marked are being received, n_tty could drop data silently (i.e.
without reporting any error to the client). This is because
characters have the potential to take up to three bytes in the line
discipline (when they get marked with parity or framing errors), but
the amount of free space reported to tty_buffer flush_to_ldisc (via
tty->receive_room) is based on the pre-marked data size.

With this patch, the n_tty layer will no longer assume that each byte
will only take up one byte in the line discipline. Instead, it will
make an overly conservative estimate that each byte will take up
three bytes in the line discipline when PARMRK is set.

Signed-off-by: Jaeden Amero 
Acked-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: Fix possible race in n_tty_read()

2012-08-10T20:13:11+00:00

Fix possible panic caused by unlocked access to tty->read_cnt in
while-loop condition in n_tty_read().

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

tty: move the termios object into the tty

2012-07-16T20:00:41+00:00

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

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

tty: note race we need to fix

2012-06-27T02:25:38+00:00

This was identified by Vincent Pillet with a high speed interface that uses
low latency mode. In the low latency case we have a tiny race but it can
be hit.

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

TTY: n_tty, do not dereference user buffer

2012-04-30T02:13:54+00:00

copy_from_read_buf currently copies data to a user buffer and then
checks if the data is single EOF. But it checks it by accessing the
user buffer. First, the buffer may be changed by other threads of the
user program already. Second, it accesses the buffer without any
checks. It might be write-only for example.

Fix this by inspecting contents of the tty (kernel) buffer instead.
Note that "n == 1" is necessary, but not sufficient. But we check
later that there is nothing left by "!tty->read_cnt" condition.

There is still an issue with the current code that EOF being wrapped
to the start of the circular buffer will result in an inappropriate
losing of the EOF character. But this is not intended to be fixed by
this patch.

Signed-off-by: Jiri Slaby 
Reported-by: Emil Goode 
Cc: Howard Chu 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03+00:00

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *`

Signed-off-by: David Howells

drivers/tty: Remove unneeded spaces

2011-12-10T03:11:35+00:00

coding style fixes in n_tty.c

Signed-off-by: Maximilian Kr�ger 
Signed-off-by: Thorsten Wi�mann 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

2011-07-26T06:09:27+00:00

* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (26 commits)
  amba pl011: workaround for uart registers lockup
  n_gsm: fix the wrong FCS handling
  pch_uart: add missing comment about OKI ML7223
  pch_uart: Add MSI support
  tty: fix "IRQ45: nobody cared"
  PTI feature to allow user to name and mark masterchannel request.
  0 for o PTI Makefile bug.
  tty: serial: samsung.c remove legacy PM code.
  SERIAL: SC26xx: Fix link error.
  serial: mrst_max3110: initialize waitqueue earlier
  mrst_max3110: Change max missing message priority.
  tty: s5pv210: Add delay loop on fifo reset function for UART
  tty/serial: Fix XSCALE serial ports, e.g. ce4100
  serial: bfin_5xx: fix off-by-one with resource size
  drivers/tty: use printk_ratelimited() instead of printk_ratelimit()
  tty: n_gsm: Added refcount usage to gsm_mux and gsm_dlci structs
  tty: n_gsm: Add raw-ip support
  tty: n_gsm: expose gsmtty device nodes at ldisc open time
  pch_phub: Fix register miss-setting issue
  serial: 8250, increase PASS_LIMIT
  ...

tty: fix "IRQ45: nobody cared"

2011-07-01T22:40:19+00:00

Unthrottling the TTY during close ends up enabling interrupts
on a device not on the active list, which will never have the
interrupts cleared.  Doctor, it hurts when I do this.

>>> On 6/2/2011 at 01:56 AM, in message <20110601145608.3e586e16@bob.linux.org.uk>, Alan Cox  wrote:
> On Wed, 01 Jun 2011 10:34:07 +1200
> "andrew mcgregor"  wrote:
> > The LKML message
> > http://kerneltrap.org/mailarchive/linux-kernel/2010/2/25/4541847 from
> > February doesn't seem to have been resolved since.  We struck the
> > issue, and the patch below (against 2.6.32) fixes it.  Should I
> > supply a patch against 3.0.0rc?
>
> I think that would be sensible. I don't actually see how you hit it as
> the IRQ ought to be masked by then but it's certainly wrong for n_tty
> to be calling into check_unthrottle at that point.
>
> So yes please send a patch with a suitable Signed-off-by: line to
> linux-serial and cc GregKH  as well.
>
> Alan

Signed-off-by: Andrew McGregor 
Signed-off-by: Greg Kroah-Hartman