From: Sreekanth Reddy sreekanth.reddy@broadcom.com
[ Upstream commit 5feed64f9199ff90c4239971733f23f30aeb2484 ]
While reenabling the IRQ after irq poll there may be small time window where HBA firmware has posted some replies and raise the interrupts but driver has not received the interrupts. So we may observe I/O timeouts as the driver has not processed the replies as interrupts got missed while reenabling the IRQ.
To fix this issue the driver has to go for one more round of processing the reply descriptors from reply descriptor post queue after enabling the IRQ.
Link: https://lore.kernel.org/r/20201102072746.27410-1-sreekanth.reddy@broadcom.co... Reported-by: Tomas Henzl thenzl@redhat.com Reviewed-by: Tomas Henzl thenzl@redhat.com Signed-off-by: Sreekanth Reddy sreekanth.reddy@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/mpt3sas/mpt3sas_base.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index e86682dc34eca..87d05c1950870 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1742,6 +1742,13 @@ _base_irqpoll(struct irq_poll *irqpoll, int budget) reply_q->irq_poll_scheduled = false; reply_q->irq_line_enable = true; enable_irq(reply_q->os_irq); + /* + * Go for one more round of processing the + * reply descriptor post queue incase if HBA + * Firmware has posted some reply descriptors + * while reenabling the IRQ. + */ + _base_process_reply_queue(reply_q); }
return num_entries;