[PATCH 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

Jaegeuk Kim
2021-01-06T19:37:36Z

When gate_work/ungate_work gets an error during hibern8_enter or exit,
ufshcd_err_handler()
ufshcd_scsi_block_requests()
ufshcd_reset_and_restore()
ufshcd_clear_ua_wluns() -> stuck
ufshcd_scsi_unblock_requests()

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

Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
drivers/scsi/ufs/ufshcd.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index bedb822a40a3..1678cec08b51 100644
--- 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;
}
@@ -6003,6 +6005,9 @@ 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);
}

/**
@@ -6940,14 +6945,11 @@ 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);
@@ -8777,6 +8779,7 @@ 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) {
@@ -8887,6 +8890,8 @@ 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);

--
2.29.2.729.g45daf8777d-goog