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: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e31d2c5..cff4f52 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -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 @@ skip_err_handling:
        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 @@ out:
                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 @@ enable_gating:
                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);