diff options
| -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 7520bc6f3871..540f6d0bb754 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); |