[PATCH v3 27/32] cxlflash: Fix to prevent stale AFU RRQ

Matthew R. Ochs mrochs at linux.vnet.ibm.com
Fri Sep 25 05:42:06 AEST 2015

Following an adapter reset, the AFU RRQ that resides in host memory
holds stale data. This can lead to a condition where the RRQ interrupt
handler tries to process stale entries and/or endlessly loops due to an
out of sync generation bit.

To fix, the AFU RRQ in host memory needs to be cleared after each reset.

Signed-off-by: Matthew R. Ochs <mrochs at linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj at linux.vnet.ibm.com>
Reviewed-by: Brian King <brking at linux.vnet.ibm.com>
 drivers/scsi/cxlflash/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 24aedfb..ab11ee6 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -1598,6 +1598,9 @@ static int start_afu(struct cxlflash_cfg *cfg)
+	/* After an AFU reset, RRQ entries are stale, clear them */
+	memset(&afu->rrq_entry, 0, sizeof(afu->rrq_entry));
 	/* Initialize RRQ pointers */
 	afu->hrrq_start = &afu->rrq_entry[0];
 	afu->hrrq_end = &afu->rrq_entry[NUM_RRQ_ENTRY - 1];

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