[PATCH 4.19 050/271] s390/qdio: handle PENDING state for QEBSM devices

[Greg Kroah-Hartman]

[ Upstream commit 04310324c6f482921c071444833e70fe861b73d9 ]

When a CQ-enabled device uses QEBSM for SBAL state inspection,
get_buf_states() can return the PENDING state for an Output Queue.
get_outbound_buffer_frontier() isn't prepared for this, and any PENDING
buffer will permanently stall all further completion processing on this
Queue.

This isn't a concern for non-QEBSM devices, as get_buf_states() for such
devices will manually turn PENDING buffers into EMPTY ones.

Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/s390/cio/qdio_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 9c7d9da42ba0..4ac4a73037f5 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -749,6 +749,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
 
 	switch (state) {
 	case SLSB_P_OUTPUT_EMPTY:
+	case SLSB_P_OUTPUT_PENDING:
 		/* the adapter got it */
 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr,
 			"out empty:%1d %02x", q->nr, count);
-- 
2.20.1