scsi: ufs: atomic update for clkgating_enable

Bug: 134949663
Bug: 137150088
Bug: 149155051
Test: test with powerhint feature
Change-Id: Ie5002107a69e7d56a889138eec0e593de1bf6a61
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Signed-off-by: Leo Liou <leoliou@google.com>
[dereference23: Apply to msm-4.14]
Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

drivers/scsi/ufs/ufshcd.c

@@ -2929,19 +2929,19 @@ 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, false);
-	} else {
-		spin_lock_irqsave(hba->host->host_lock, flags);
+	if (value)
+		hba->clk_gating.active_reqs--;
+	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;
 }