Merge "scsi: ufs: fix deadlock between clock scaling and shutdown" (a51b7f60) · Commits · e / devices / android_kernel_sony_msm8998

drivers/scsi/ufs/ufshcd.c

+33 −10

Original line number	Diff line number	Diff line
		@@ -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);