diff mbox

[v6,27/37] cxlflash: Fix to prevent stale AFU RRQ

Message ID 1445458514-58777-1-git-send-email-mrochs@linux.vnet.ibm.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Matthew R. Ochs Oct. 21, 2015, 8:15 p.m. UTC 
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@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
---
 drivers/scsi/cxlflash/main.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Tomas Henzl Oct. 23, 2015, 1:55 p.m. UTC | #1 
On 21.10.2015 22:15, Matthew R. Ochs wrote:
> 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@linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
> Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
> Reviewed-by: Daniel Axtens <dja@axtens.net>

Reviewed-by: Tomas Henzl <thenzl@redhat.com>

Tomas

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index eeb1c47..c77cb92 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)
 
 	init_pcr(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];