Merge "scsi: ufs: fix deadlock between clock scaling and shutdown"

1 files changed, 33 insertions, 10 deletions

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2138e81bb9e9..d46682bb1d84 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8904,6 +8904,35 @@ static inline void ufshcd_add_sysfs_nodes(struct ufs_hba *hba)
 	ufshcd_add_spm_lvl_sysfs_nodes(hba);
 }
 
+static void ufshcd_shutdown_clkscaling(struct ufs_hba *hba)
+{
+	bool suspend = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (hba->clk_scaling.is_allowed) {
+		hba->clk_scaling.is_allowed = false;
+		suspend = true;
+	}
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/**
+	 * Scaling may be scheduled before, hence make sure it
+	 * doesn't race with shutdown
+	 */
+	if (ufshcd_is_clkscaling_supported(hba)) {
+		device_remove_file(hba->dev, &hba->clk_scaling.enable_attr);
+		cancel_work_sync(&hba->clk_scaling.suspend_work);
+		cancel_work_sync(&hba->clk_scaling.resume_work);
+		if (suspend)
+			ufshcd_suspend_clkscaling(hba);
+	}
+
+	/* Unregister so that devfreq_monitor can't race with shutdown */
+	if (hba->devfreq)
+		devfreq_remove_device(hba->devfreq);
+}
+
 /**
  * ufshcd_shutdown - shutdown routine
  * @hba: per adapter instance
@@ -8921,16 +8950,14 @@ int ufshcd_shutdown(struct ufs_hba *hba)
 
 	pm_runtime_get_sync(hba->dev);
 	ufshcd_hold_all(hba);
+	ufshcd_mark_shutdown_ongoing(hba);
+	ufshcd_shutdown_clkscaling(hba);
 	/**
-	 * (1) Set state to shutting down
-	 * (2) Acquire the lock to stop any more requests
-	 * (3) Suspend clock scaling
-	 * (4) Wait for all issued requests to complete
+	 * (1) Acquire the lock to stop any more requests
+	 * (2) Wait for all issued requests to complete
 	 */
-	ufshcd_mark_shutdown_ongoing(hba);
 	ufshcd_get_write_lock(hba);
 	ufshcd_scsi_block_requests(hba);
-	ufshcd_suspend_clkscaling(hba);
 	ret = ufshcd_wait_for_doorbell_clr(hba, U64_MAX);
 	if (ret)
 		dev_err(hba->dev, "%s: waiting for DB clear: failed: %d\n",
@@ -9373,10 +9400,6 @@ static void ufshcd_clk_scaling_resume_work(struct work_struct *work)
 					   clk_scaling.resume_work);
 	unsigned long irq_flags;
 
-	/* Let's not resume scaling if shutdown is ongoing */
-	if (ufshcd_is_shutdown_ongoing(hba))
-		return;
-
 	spin_lock_irqsave(hba->host->host_lock, irq_flags);
 	if (!hba->clk_scaling.is_suspended) {
 		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);