From 563c853944c49fd4ef847f722ab97ad6760a58f7 Mon Sep 17 00:00:00 2001 From: Tomas Henzl Date: Mon, 23 Nov 2020 17:12:04 -0500 Subject: [PATCH 19/33] [scsi] scsi: mpt3sas: Fix timeouts observed while reenabling IRQ Message-id: <20201123171204.21755-2-thenzl@redhat.com> Patchwork-id: 341324 Patchwork-instance: patchwork O-Subject: [RHEL8.4 e-stor PATCH 1/1] scsi: mpt3sas: Fix timeouts observed while reenabling IRQ Bugzilla: 1880114 RH-Acked-by: Maurizio Lombardi RH-Acked-by: David Milburn 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.com Reported-by: Tomas Henzl Reviewed-by: Tomas Henzl Signed-off-by: Sreekanth Reddy Signed-off-by: Martin K. Petersen (cherry picked from commit 5feed64f9199ff90c4239971733f23f30aeb2484) Signed-off-by: Tomas Henzl Signed-off-by: Jan Stancek --- 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 b096917fc314..a0ab44d520f6 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1740,6 +1740,13 @@ _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; -- 2.13.6