From: Venkat Gopalakrishnan <venk...@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 <venk...@codeaurora.org>
Signed-off-by: Asutosh Das <asuto...@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 987b81b..4d4c7d6 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5406,19 +5406,30 @@ 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.

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