From: Jaegeuk Kim <jaeg...@google.com>

[ Upstream commit b664511297644eac34038df877b3ad7bcaa81913 ]

While running a stress test which enables/disables clkgating, we
occasionally hit device timeout. This patch avoids a subtle race condition
to address it.

Link: https://lore.kernel.org/r/20201117165839.1643377-3-jaeg...@kernel.org
Reviewed-by: Can Guo <c...@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaeg...@google.com>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/scsi/ufs/ufshcd.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 675e16e61ebdd..ed07e52fa861b 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1751,19 +1751,19 @@ static ssize_t ufshcd_clkgate_enable_store(struct 
device *dev,
                return -EINVAL;
 
        value = !!value;
+
+       spin_lock_irqsave(hba->host->host_lock, flags);
        if (value == hba->clk_gating.is_enabled)
                goto out;
 
-       if (value) {
-               ufshcd_release(hba);
-       } else {
-               spin_lock_irqsave(hba->host->host_lock, flags);
+       if (value)
+               __ufshcd_release(hba);
+       else
                hba->clk_gating.active_reqs++;
-               spin_unlock_irqrestore(hba->host->host_lock, flags);
-       }
 
        hba->clk_gating.is_enabled = value;
 out:
+       spin_unlock_irqrestore(hba->host->host_lock, flags);
        return count;
 }
 
-- 
2.27.0

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