diff options
| author | Julian Wiedmann <jwi@linux.ibm.com> | 2019-07-11 18:17:36 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-25 10:52:47 +0200 |
| commit | f34ef4fb5d307d211ad93b232a94c27bd5cda4af (patch) | |
| tree | 1d6d1c6baa1db601ecf0eb1a5f9603a1a8a529e4 /drivers/s390 | |
| parent | e1c7e4efbbf873fcb9000dfd5f506a501d034cdc (diff) | |
s390/qdio: add sanity checks to the fast-requeue path
[ Upstream commit a6ec414a4dd529eeac5c3ea51c661daba3397108 ]
If the device driver were to send out a full queue's worth of SBALs,
current code would end up discovering the last of those SBALs as PRIMED
and erroneously skip the SIGA-w. This immediately stalls the queue.
Add a check to not attempt fast-requeue in this case. While at it also
make sure that the state of the previous SBAL was successfully extracted
before inspecting it.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/cio/qdio_main.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 8d7fc3b6ca63..adf322a86a01 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -1576,13 +1576,13 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags, rc = qdio_kick_outbound_q(q, phys_aob); } else if (need_siga_sync(q)) { rc = qdio_siga_sync_q(q); + } else if (count < QDIO_MAX_BUFFERS_PER_Q && + get_buf_state(q, prev_buf(bufnr), &state, 0) > 0 && + state == SLSB_CU_OUTPUT_PRIMED) { + /* The previous buffer is not processed yet, tack on. */ + qperf_inc(q, fast_requeue); } else { - /* try to fast requeue buffers */ - get_buf_state(q, prev_buf(bufnr), &state, 0); - if (state != SLSB_CU_OUTPUT_PRIMED) - rc = qdio_kick_outbound_q(q, 0); - else - qperf_inc(q, fast_requeue); + rc = qdio_kick_outbound_q(q, 0); } /* in case of SIGA errors we must process the error immediately */ |