diff options
| -rw-r--r-- | drivers/s390/cio/qdio_main.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index be93172555ec..7b7620de2acd 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -205,17 +205,22 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr, int auto_ack, int merge_pending) { unsigned char __state = 0; - int i; + int i = 1; if (is_qebsm(q)) return qdio_do_eqbs(q, state, bufnr, count, auto_ack); /* get initial state: */ __state = q->slsb.val[bufnr]; + + /* Bail out early if there is no work on the queue: */ + if (__state & SLSB_OWNER_CU) + goto out; + if (merge_pending && __state == SLSB_P_OUTPUT_PENDING) __state = SLSB_P_OUTPUT_EMPTY; - for (i = 1; i < count; i++) { + for (; i < count; i++) { bufnr = next_buf(bufnr); /* merge PENDING into EMPTY: */ @@ -228,6 +233,8 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr, if (q->slsb.val[bufnr] != __state) break; } + +out: *state = __state; return i; } |