path: root/drivers/s390/cio/qdio_main.c
diff options
authorJulian Wiedmann <jwi@linux.ibm.com>2019-04-01 10:08:08 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2019-05-08 15:01:23 +0200
commit3060781f2664d34af641247aeac62696405a3fde (patch)
tree6dc9b7de3d10a5226862c867801b2aa58059a62f /drivers/s390/cio/qdio_main.c
parents390/cio: Remove tracing for rchp instruction (diff)
s390/qdio: allow to scan all Output SBALs in one go
Old code restricted the number of inspected SBALs to QDIO_MAX_BUFFERS_PER_Q - 1, as otherwise the first_to_check and first_to_kick cursors could overlap. Subsequent code would then assume that there was no progress on the queue, when in fact _all_ SBALs on the queue were ready-to-process. This limitation no longer applies, so allow the queue-scan code to inspect all SBALs on the queue. Note that qeth requires an additional patch ("s390/qeth: stop/wake TX queues based on their fill level"), to avoid potential queue stalls when all 128 SBALs are reported as ready-to-process. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to '')
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index cfce255521ac..957c2a8dfc13 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -719,11 +719,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q, unsigned int start)
- /*
- * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
- * would return 0.
- */
- count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
+ count = atomic_read(&q->nr_buf_used);
if (!count)
return 0;