diff options
Diffstat (limited to 'drivers/isdn/gigaset/common.c')
| -rw-r--r-- | drivers/isdn/gigaset/common.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c index 2ea4976aa02..5155c5b07a0 100644 --- a/drivers/isdn/gigaset/common.c +++ b/drivers/isdn/gigaset/common.c @@ -521,6 +521,47 @@ static void gigaset_inbuf_init(struct inbuf_t *inbuf, struct bc_state *bcs, inbuf->inputstate = inputstate; } +/* append received bytes to inbuf */ +int gigaset_fill_inbuf(struct inbuf_t *inbuf, const unsigned char *src, + unsigned numbytes) +{ + unsigned n, head, tail, bytesleft; + + gig_dbg(DEBUG_INTR, "received %u bytes", numbytes); + + if (!numbytes) + return 0; + + bytesleft = numbytes; + tail = atomic_read(&inbuf->tail); + head = atomic_read(&inbuf->head); + gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail); + + while (bytesleft) { + if (head > tail) + n = head - 1 - tail; + else if (head == 0) + n = (RBUFSIZE-1) - tail; + else + n = RBUFSIZE - tail; + if (!n) { + dev_err(inbuf->cs->dev, + "buffer overflow (%u bytes lost)", bytesleft); + break; + } + if (n > bytesleft) + n = bytesleft; + memcpy(inbuf->data + tail, src, n); + bytesleft -= n; + tail = (tail + n) % RBUFSIZE; + src += n; + } + gig_dbg(DEBUG_INTR, "setting tail to %u", tail); + atomic_set(&inbuf->tail, tail); + return numbytes != bytesleft; +} +EXPORT_SYMBOL_GPL(gigaset_fill_inbuf); + /* Initialize the b-channel structure */ static struct bc_state *gigaset_initbcs(struct bc_state *bcs, struct cardstate *cs, int channel) |