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* [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ
@ 2015-09-16 17:05 Matthew R. Ochs
  0 siblings, 0 replies; 3+ messages in thread
From: Matthew R. Ochs @ 2015-09-16 17:05 UTC (permalink / raw)
  To: linux-scsi, James.Bottomley, nab, brking, imunsie, dja,
	andrew.donnellan
  Cc: mikey, linuxppc-dev, Manoj N. Kumar

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>
---
 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 a5b45ed..0487fac 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -1609,6 +1609,9 @@ 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];
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ
  2015-09-16 21:23 [PATCH v2 00/30] cxlflash: Miscellaneous bug fixes and corrections Matthew R. Ochs
@ 2015-09-16 21:32 ` Matthew R. Ochs
  2015-09-23 19:18   ` Brian King
  0 siblings, 1 reply; 3+ messages in thread
From: Matthew R. Ochs @ 2015-09-16 21:32 UTC (permalink / raw)
  To: linux-scsi, James Bottomley, Nicholas A. Bellinger, Brian King,
	Ian Munsie, Daniel Axtens, Andrew Donnellan
  Cc: Michael Neuling, linuxppc-dev, Manoj N. Kumar

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>
---
 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 a5b45ed..0487fac 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -1609,6 +1609,9 @@ 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];
-- 
2.1.0

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ
  2015-09-16 21:32 ` [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ Matthew R. Ochs
@ 2015-09-23 19:18   ` Brian King
  0 siblings, 0 replies; 3+ messages in thread
From: Brian King @ 2015-09-23 19:18 UTC (permalink / raw)
  To: Matthew R. Ochs, linux-scsi, James Bottomley,
	Nicholas A. Bellinger, Ian Munsie, Daniel Axtens,
	Andrew Donnellan
  Cc: Michael Neuling, linuxppc-dev, Manoj N. Kumar

Reviewed-by: Brian King <brking@linux.vnet.ibm.com>

-- 
Brian King
Power Linux I/O
IBM Linux Technology Center

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2015-09-23 20:46 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2015-09-16 17:05 [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ Matthew R. Ochs
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2015-09-16 21:23 [PATCH v2 00/30] cxlflash: Miscellaneous bug fixes and corrections Matthew R. Ochs
2015-09-16 21:32 ` [PATCH v2 28/30] cxlflash: Fix to prevent stale AFU RRQ Matthew R. Ochs
2015-09-23 19:18   ` Brian King

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