lkml.org 
[lkml]   [2015]   [Jul]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2] isdn/gigaset: reset tty->receive_room when attaching ser_gigaset
From
Date
Hello.

On 7/14/2015 1:37 AM, Tilman Schmidt wrote:

> Commit 79901317ce80 ("n_tty: Don't flush buffer when closing ldisc"),
> first merged in kernel release 3.10, caused the following regression
> in the Gigaset M101 driver:

> Before that commit, when closing the N_TTY line discipline in
> preparation to switching to N_GIGASET_M101, receive_room would be
> reset to a non-zero value by the call to n_tty_flush_buffer() in
> n_tty's close method. With the removal of that call, receive_room
> might be left at zero, blocking data reception on the serial line.

> The present patch fixes that regression by setting receive_room
> to an appropriate value in the ldisc open method.

> Fixes: 79901317ce80 ("n_tty: Don't flush buffer when closing ldisc")
> Signed-off-by: Tilman Schmidt <tilman@imap.cc>
> ---
> drivers/isdn/gigaset/ser-gigaset.c | 11 ++++++++++-
> 1 files changed, 10 insertions(+), 1 deletions(-)

> diff --git a/drivers/isdn/gigaset/ser-gigaset.c b/drivers/isdn/gigaset/ser-gigaset.c
> index 8c91fd5..3ac9c41 100644
> --- a/drivers/isdn/gigaset/ser-gigaset.c
> +++ b/drivers/isdn/gigaset/ser-gigaset.c
> @@ -524,9 +524,18 @@ gigaset_tty_open(struct tty_struct *tty)
> cs->hw.ser->tty = tty;
> atomic_set(&cs->hw.ser->refcnt, 1);
> init_completion(&cs->hw.ser->dead_cmp);
> -

Unrelated change?

> tty->disc_data = cs;
>
> + /* Set the amount of data we're willing to receive per call
> + * from the hardware driver to half of the input buffer size
> + * to leave some reserve.
> + * Note: We don't do flow control towards the hardware driver.
> + * If more data is received than will fit into the input buffer,
> + * it will be dropped and an error will be logged. This should
> + * never happen as the device is slow and the buffer size ample.
> + */
> + tty->receive_room = RBUFSIZE/2;

The general kernel coding style is to surround operators with spaces.

[...]

MBR, Sergei



\
 
 \ /
  Last update: 2015-07-14 15:21    [W:0.120 / U:0.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site