Commit 4ee7ee53 authored by Jaegeuk Kim's avatar Jaegeuk Kim Committed by Martin K. Petersen
Browse files

scsi: ufs: Fix livelock of ufshcd_clear_ua_wluns() 

When gate_work/ungate_work experience an error during hibern8_enter or exit
we can livelock:

 ufshcd_err_handler()
   ufshcd_scsi_block_requests()
   ufshcd_reset_and_restore()
     ufshcd_clear_ua_wluns() -> stuck
   ufshcd_scsi_unblock_requests()

In order to avoid this, ufshcd_clear_ua_wluns() can be called per recovery
flows such as suspend/resume, link_recovery, and error_handler.

Link: https://lore.kernel.org/r/20210107185316.788815-2-jaegeuk@kernel.org


Fixes: 1918651f ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")
Reviewed-by: default avatarCan Guo <cang@codeaurora.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 901d01c8

drivers/scsi/ufs/ufshcd.c

+12 −7
Original line number Diff line number Diff line
@@ -3996,6 +3996,8 @@ int ufshcd_link_recovery(struct ufs_hba *hba) 
	if (ret)

		dev_err(hba->dev, "%s: link recovery failed, err %d",

			__func__, ret);

	else

		ufshcd_clear_ua_wluns(hba);



	return ret;

}
@@ -6001,6 +6003,9 @@ static void ufshcd_err_handler(struct work_struct *work) 
	ufshcd_scsi_unblock_requests(hba);

	ufshcd_err_handling_unprepare(hba);

	up(&hba->eh_sem);



	if (!err && needs_reset)

		ufshcd_clear_ua_wluns(hba);

}



/**
@@ -6938,14 +6943,11 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba) 
	ufshcd_set_clk_freq(hba, true);



	err = ufshcd_hba_enable(hba);

	if (err)

		goto out;



	/* Establish the link again and restore the device */

	err = ufshcd_probe_hba(hba, false);

	if (!err)

		ufshcd_clear_ua_wluns(hba);

out:

		err = ufshcd_probe_hba(hba, false);



	if (err)

		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);

	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);
@@ -7716,6 +7718,8 @@ static int ufshcd_add_lus(struct ufs_hba *hba) 
	if (ret)

		goto out;



	ufshcd_clear_ua_wluns(hba);



	/* Initialize devfreq after UFS device is detected */

	if (ufshcd_is_clkscaling_supported(hba)) {

		memcpy(&hba->clk_scaling.saved_pwr_info.info,
@@ -7917,8 +7921,6 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie) 
		pm_runtime_put_sync(hba->dev);

		ufshcd_exit_clk_scaling(hba);

		ufshcd_hba_exit(hba);

	} else {

		ufshcd_clear_ua_wluns(hba);

	}

}
@@ -8775,6 +8777,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) 
		ufshcd_resume_clkscaling(hba);

	hba->clk_gating.is_suspended = false;

	hba->dev_info.b_rpm_dev_flush_capable = false;

	ufshcd_clear_ua_wluns(hba);

	ufshcd_release(hba);

out:

	if (hba->dev_info.b_rpm_dev_flush_capable) {
@@ -8885,6 +8888,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op) 
		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);

	}



	ufshcd_clear_ua_wluns(hba);



	/* Schedule clock gating in case of no access to UFS device yet */

	ufshcd_release(hba);