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-rw-r--r--drivers/isdn/gigaset/common.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 2ea4976..5155c5b 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)
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