[PATCH v5.10] scsi: core: ufs: Fix a hang in the error handler

[Shivani Agarwal <shivani.agarwal@broadcom.com>]

From: Sanjeev Yadav <sanjeev.y@mediatek.com>

[ Upstream commit 8a3514d348de87a9d5e2ac00fbac4faae0b97996 ]

ufshcd_err_handling_prepare() calls ufshcd_rpm_get_sync(). The latter
function can only succeed if UFSHCD_EH_IN_PROGRESS is not set because
resuming involves submitting a SCSI command and ufshcd_queuecommand()
returns SCSI_MLQUEUE_HOST_BUSY if UFSHCD_EH_IN_PROGRESS is set. Fix this
hang by setting UFSHCD_EH_IN_PROGRESS after ufshcd_rpm_get_sync() has
been called instead of before.

Backtrace:
__switch_to+0x174/0x338
__schedule+0x600/0x9e4
schedule+0x7c/0xe8
schedule_timeout+0xa4/0x1c8
io_schedule_timeout+0x48/0x70
wait_for_common_io+0xa8/0x160 //waiting on START_STOP
wait_for_completion_io_timeout+0x10/0x20
blk_execute_rq+0xe4/0x1e4
scsi_execute_cmd+0x108/0x244
ufshcd_set_dev_pwr_mode+0xe8/0x250
__ufshcd_wl_resume+0x94/0x354
ufshcd_wl_runtime_resume+0x3c/0x174
scsi_runtime_resume+0x64/0xa4
rpm_resume+0x15c/0xa1c
__pm_runtime_resume+0x4c/0x90 // Runtime resume ongoing
ufshcd_err_handler+0x1a0/0xd08
process_one_work+0x174/0x808
worker_thread+0x15c/0x490
kthread+0xf4/0x1ec
ret_from_fork+0x10/0x20

Signed-off-by: Sanjeev Yadav <sanjeev.y@mediatek.com>
[ bvanassche: rewrote patch description ]
Fixes: 62694735ca95 ("[SCSI] ufs: Add runtime PM support for UFS host controller driver")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20250523201409.1676055-1-bvanassche@acm.org
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[Shivani: Modified to apply on 5.10.y]
Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com>
---
 drivers/scsi/ufs/ufshcd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 54e7d96bf..c1f232472 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5766,10 +5766,12 @@ static void ufshcd_err_handler(struct work_struct *work)
 		spin_unlock_irqrestore(hba->host->host_lock, flags);
 		return;
 	}
-	ufshcd_set_eh_in_progress(hba);
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
 	ufshcd_err_handling_prepare(hba);
+
 	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_set_eh_in_progress(hba);
 	ufshcd_scsi_block_requests(hba);
 	/*
 	 * A full reset and restore might have happened after preparation
-- 
2.40.4