diff options
| author | Tilman Schmidt <tilman@imap.cc> | 2015-07-14 00:37:13 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-16 02:24:45 +0200 |
| commit | fd98e9419d8d622a4de91f76b306af6aa627aa9c (patch) | |
| tree | e9047d514d1ba80a6aad4027860dd1c4d4e3f42a /drivers/isdn/gigaset/ser-gigaset.c | |
| parent | fq_codel: fix a use-after-free (diff) | |
| download | linux-fd98e9419d8d622a4de91f76b306af6aa627aa9c.tar.xz linux-fd98e9419d8d622a4de91f76b306af6aa627aa9c.zip | |
isdn/gigaset: reset tty->receive_room when attaching ser_gigaset
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn/gigaset/ser-gigaset.c')
| -rw-r--r-- | 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 8c91fd5eb6fd..3ac9c4194814 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); - 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; + /* OK.. Initialization of the datastructures and the HW is done.. Now * startup system and notify the LL that we are ready to run */ |