From b52d695d062095327b944acf7daabbc816ab319b Mon Sep 17 00:00:00 2001 From: Stanley Jhu Date: Sat, 12 Sep 2026 21:16:25 +0800 Subject: [PATCH] scsi: ufs: core: Keep internal commands dispatchable during error handling Commit 08b12cda6c44 ("scsi: ufs: core: Switch to scsi_get_internal_cmd()") switched UFS internal commands to allocate requests on hba->host->pseudo_sdev->request_queue, which shares the host tagset with regular LUNs. During error recovery, ufshcd_err_handling_prepare() calls blk_mq_quiesce_tagset(&hba->host->tag_set), marking all queues in the tagset as quiesced, including pseudo_sdev->request_queue. When ufshcd_verify_dev_init() subsequently issues internal commands (e.g. NOP OUT UPIU) via blk_execute_rq(), blk_mq_run_hw_queue() skips running the quiesced queue, resulting in an unrecoverable circular wait deadlock. Keep quiescing the tagset and unquiesce the pseudo SCSI device on top of that, so internal commands stay dispatchable while the logical units remain quiesced. Re-quiesce the pseudo device before unquiescing the tagset so that quiesce_depth stays balanced. Clock scaling and ufshcd_pause_command_processing() are unaffected: they keep quiescing the whole tagset, internal commands included. Fixes: 08b12cda6c44 ("scsi: ufs: core: Switch to scsi_get_internal_cmd()") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/6f78c4bd-a70b-402d-abfd-599091b67674@acm.org/ Signed-off-by: Stanley Jhu Reviewed-by: Bart Van Assche Link: https://patch.msgid.link/20260912131625.2301486-1-stanleyjhu@google.com Signed-off-by: Martin K. Petersen (Oracle) --- drivers/ufs/core/ufshcd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 2ba244cf40ac..54f4e7d7de02 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -6817,11 +6817,17 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba) } /* Wait for ongoing ufshcd_queuecommand() calls to finish. */ blk_mq_quiesce_tagset(&hba->host->tag_set); + /* + * Internal commands are submitted on the pseudo SCSI device. Let them + * through so that the error handler can recover the link. + */ + blk_mq_unquiesce_queue(hba->host->pseudo_sdev->request_queue); cancel_work_sync(&hba->eeh_work); } static void ufshcd_err_handling_unprepare(struct ufs_hba *hba) { + blk_mq_quiesce_queue_nowait(hba->host->pseudo_sdev->request_queue); blk_mq_unquiesce_tagset(&hba->host->tag_set); ufshcd_release(hba); if (ufshcd_is_clkscaling_supported(hba))