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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tomas Henzl <thenzl@redhat.com>,
        kernel test robot <lkp@intel.com>,
        Chandrakanth Patil <chandrakanth.patil@broadcom.com>,
        Sumit Saxena <sumit.saxena@broadcom.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 029/149] scsi: megaraid_sas: Handle missing interrupts while re-enabling IRQs
Date:   Mon, 19 Jul 2021 16:52:17 +0200
Message-Id: <20210719144908.436534436@linuxfoundation.org>
In-Reply-To: <20210719144901.370365147@linuxfoundation.org>
References: <20210719144901.370365147@linuxfoundation.org>
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From: Chandrakanth Patil <chandrakanth.patil@broadcom.com>

[ Upstream commit 9bedd36e9146b34dda4d6994e3aa1d72bc6442c1 ]

While reenabling the IRQ after IRQ poll there may be a small window for the
firmware to post the replies with interrupts raised. In that case the
driver will not see the interrupts which leads to I/O timeout.

This issue only happens when there are many I/O completions on a single
reply queue. This forces the driver to switch between the interrupt and IRQ
context.

Make the driver process the reply queue one more time after enabling the
IRQ.

Link: https://lore.kernel.org/linux-scsi/20201102072746.27410-1-sreekanth.reddy@broadcom.com/
Link: https://lore.kernel.org/r/20210528131307.25683-5-chandrakanth.patil@broadcom.com
Cc: Tomas Henzl <thenzl@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/megaraid/megaraid_sas_fusion.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index ae7a3e154bb2..a78a702511fa 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -3716,6 +3716,7 @@ static void megasas_sync_irqs(unsigned long instance_addr)
 		if (irq_ctx->irq_poll_scheduled) {
 			irq_ctx->irq_poll_scheduled = false;
 			enable_irq(irq_ctx->os_irq);
+			complete_cmd_fusion(instance, irq_ctx->MSIxIndex, irq_ctx);
 		}
 	}
 }
@@ -3747,6 +3748,7 @@ int megasas_irqpoll(struct irq_poll *irqpoll, int budget)
 		irq_poll_complete(irqpoll);
 		irq_ctx->irq_poll_scheduled = false;
 		enable_irq(irq_ctx->os_irq);
+		complete_cmd_fusion(instance, irq_ctx->MSIxIndex, irq_ctx);
 	}
 
 	return num_entries;
@@ -3763,6 +3765,7 @@ megasas_complete_cmd_dpc_fusion(unsigned long instance_addr)
 {
 	struct megasas_instance *instance =
 		(struct megasas_instance *)instance_addr;
+	struct megasas_irq_context *irq_ctx = NULL;
 	u32 count, MSIxIndex;
 
 	count = instance->msix_vectors > 0 ? instance->msix_vectors : 1;
@@ -3771,8 +3774,10 @@ megasas_complete_cmd_dpc_fusion(unsigned long instance_addr)
 	if (atomic_read(&instance->adprecovery) == MEGASAS_HW_CRITICAL_ERROR)
 		return;
 
-	for (MSIxIndex = 0 ; MSIxIndex < count; MSIxIndex++)
-		complete_cmd_fusion(instance, MSIxIndex, NULL);
+	for (MSIxIndex = 0 ; MSIxIndex < count; MSIxIndex++) {
+		irq_ctx = &instance->irq_context[MSIxIndex];
+		complete_cmd_fusion(instance, MSIxIndex, irq_ctx);
+	}
 }
 
 /**
-- 
2.30.2