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From: Asutosh Das <asutoshd@codeaurora.org>
To: subhashj@codeaurora.org, cang@codeaurora.org,
	vivek.gautam@codeaurora.org, rnayak@codeaurora.org,
	vinholikatti@gmail.com, jejb@linux.vnet.ibm.com,
	martin.petersen@oracle.com, asutoshd@codeaurora.org,
	linux-mmc@vger.kernel.org
Cc: linux-scsi@vger.kernel.org,
	Venkat Gopalakrishnan <venkatg@codeaurora.org>,
	linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v2 08/10] scsi: ufs: make sure all interrupts are processed
Date: Thu,  3 May 2018 16:37:20 +0530	[thread overview]
Message-ID: <faa728f587df5372dd78b3d012ed6bf78e92e883.1525343531.git.asutoshd@codeaurora.org> (raw)
In-Reply-To: <cover.1525341340.git.asutoshd@codeaurora.org>
In-Reply-To: <cover.1525343531.git.asutoshd@codeaurora.org>

From: Venkat Gopalakrishnan <venkatg@codeaurora.org>

As multiple requests are submitted to the ufs host controller in
parallel there could be instances where the command completion
interrupt arrives later for a request that is already processed
earlier as the corresponding doorbell was cleared when handling
the previous interrupt. Read the interrupt status in a loop after
processing the received interrupt to catch such interrupts and
handle it.

Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c35a076..09b7a3f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5383,19 +5383,30 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 	u32 intr_status, enabled_intr_status;
 	irqreturn_t retval = IRQ_NONE;
 	struct ufs_hba *hba = __hba;
+	int retries = hba->nutrs;
 
 	spin_lock(hba->host->host_lock);
 	intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
-	enabled_intr_status =
-		intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
 
-	if (intr_status)
-		ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
+	/*
+	 * There could be max of hba->nutrs reqs in flight and in worst case
+	 * if the reqs get finished 1 by 1 after the interrupt status is
+	 * read, make sure we handle them by checking the interrupt status
+	 * again in a loop until we process all of the reqs before returning.
+	 */
+	do {
+		enabled_intr_status =
+			intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+		if (intr_status)
+			ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
+		if (enabled_intr_status) {
+			ufshcd_sl_intr(hba, enabled_intr_status);
+			retval = IRQ_HANDLED;
+		}
+
+		intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
+	} while (intr_status && --retries);
 
-	if (enabled_intr_status) {
-		ufshcd_sl_intr(hba, enabled_intr_status);
-		retval = IRQ_HANDLED;
-	}
 	spin_unlock(hba->host->host_lock);
 	return retval;
 }
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

  parent reply	other threads:[~2018-05-03 11:14 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1525341340.git.asutoshd@codeaurora.org>
     [not found] ` <cover.1525343531.git.asutoshd@codeaurora.org>
2018-05-03 11:07   ` [PATCH v2 01/10] scsi: ufs: Allowing power mode change Asutosh Das
2018-05-16 21:09     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 02/10] scsi: ufs-qcom: Enable UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE quirk Asutosh Das
2018-05-16 21:10     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 03/10] scsi: ufs: Add LCC quirk for host and device Asutosh Das
2018-05-16 21:11     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 04/10] scsi: ufs: fix exception event handling Asutosh Das
2018-05-16 21:12     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 05/10] scsi: ufshcd: fix possible unclocked register access Asutosh Das
2018-05-16 21:12     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 06/10] scsi: ufs: add reference counting for scsi block requests Asutosh Das
2018-05-16 21:13     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 07/10] scsi: ufs-qcom: remove broken hci version quirk Asutosh Das
2018-05-16 21:13     ` Subhash Jadavani
2018-05-03 11:07   ` Asutosh Das [this message]
2018-05-16 21:14     ` [PATCH v2 08/10] scsi: ufs: make sure all interrupts are processed Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 09/10] scsi: ufs: fix irq return code Asutosh Das
2018-06-28 22:26     ` Subhash Jadavani
2018-05-03 11:07   ` [PATCH v2 10/10] scsi: ufs: Add clock ungating to a separate workqueue Asutosh Das
2018-05-16 21:14     ` Subhash Jadavani

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