diff options
| author | Tilman Schmidt <tilman@imap.cc> | 2010-09-30 13:35:31 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-10-01 00:33:36 -0700 |
| commit | 4cb5e42f6132bf2d2851f8dd67bd8499979c7ebc (patch) | |
| tree | e10706e5895042010a63959dd3c48412b1c22a8b /drivers/isdn | |
| parent | 60798c68bebf6009df9da634e79ebdd8c8227238 (diff) | |
isdn/gigaset: unclog bas_gigaset AT response pipe
Recover from a lost HD_RECEIVEATDATA_ACK message by sending a
zero-length HD_READ_ATMESSAGE command when ev_layer sends "+++".
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn')
| -rw-r--r-- | drivers/isdn/gigaset/bas-gigaset.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c index 7520bc6f387..540f6d0bb75 100644 --- a/drivers/isdn/gigaset/bas-gigaset.c +++ b/drivers/isdn/gigaset/bas-gigaset.c @@ -1896,6 +1896,28 @@ static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb) * The next command will reopen the AT channel automatically. */ if (cb->len == 3 && !memcmp(cb->buf, "+++", 3)) { + /* If an HD_RECEIVEATDATA_ACK message remains unhandled + * because of an error, the base never sends another one. + * The response channel is thus effectively blocked. + * Closing and reopening the AT channel does *not* clear + * this condition. + * As a stopgap measure, submit a zero-length AT read + * before closing the AT channel. This has the undocumented + * effect of triggering a new HD_RECEIVEATDATA_ACK message + * from the base if necessary. + * The subsequent AT channel close then discards any pending + * messages. + */ + spin_lock_irqsave(&cs->lock, flags); + if (!(cs->hw.bas->basstate & BS_ATRDPEND)) { + kfree(cs->hw.bas->rcvbuf); + cs->hw.bas->rcvbuf = NULL; + cs->hw.bas->rcvbuf_size = 0; + cs->hw.bas->retry_cmd_in = 0; + atread_submit(cs, 0); + } + spin_unlock_irqrestore(&cs->lock, flags); + rc = req_submit(cs->bcs, HD_CLOSE_ATCHANNEL, 0, BAS_TIMEOUT); if (cb->wake_tasklet) tasklet_schedule(cb->wake_tasklet); |