This is a note to let you know that I've just added the patch titled scsi: ufs: Fix tm request when non-fatal error happens to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-ufs-fix-tm-request-when-non-fatal-error-happens.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From eeb1b55b6e25c5f7265ff45cd050f3bc2cc423a4 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Date: Thu, 7 Jan 2021 10:53:16 -0800 Subject: scsi: ufs: Fix tm request when non-fatal error happens From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> commit eeb1b55b6e25c5f7265ff45cd050f3bc2cc423a4 upstream. When non-fatal error like line-reset happens, ufshcd_err_handler() starts to abort tasks by ufshcd_try_to_abort_task(). When it tries to issue a task management request, we hit two warnings: WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70 WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82 blk_mq_get_tag+0x438/0x46c After fixing the above warnings we hit another tm_cmd timeout which may be caused by unstable controller state: __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out Then, ufshcd_err_handler() enters full reset, and kernel gets stuck. It turned out ufshcd_print_trs() printed too many messages on console which requires CPU locks. Likewise hba->silence_err_logs, we need to avoid too verbose messages. This is actually not an error case. Link: https://lore.kernel.org/r/20210107185316.788815-3-jaegeuk@xxxxxxxxxx Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs") Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> [Zhai: remove an item of debug print not available in v5.4] Signed-off-by: Orson Zhai <orson.zhai@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -4748,7 +4748,8 @@ ufshcd_transfer_rsp_status(struct ufs_hb break; } /* end of switch */ - if ((host_byte(result) != DID_OK) && !hba->silence_err_logs) + if ((host_byte(result) != DID_OK) && + (host_byte(result) != DID_REQUEUE) && !hba->silence_err_logs) ufshcd_print_trs(hba, 1 << lrbp->task_tag, true); return result; } @@ -5661,9 +5662,12 @@ static irqreturn_t ufshcd_intr(int irq, intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS); } - if (enabled_intr_status && retval == IRQ_NONE) { - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n", - __func__, intr_status); + if (enabled_intr_status && retval == IRQ_NONE && + !ufshcd_eh_in_progress(hba)) { + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (-, 0x%08x)\n", + __func__, + intr_status, + enabled_intr_status); ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: "); } @@ -5705,7 +5709,10 @@ static int __ufshcd_issue_tm_cmd(struct /* * blk_get_request() is used here only to get a free tag. */ - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED); + req = blk_get_request(q, REQ_OP_DRV_OUT, 0); + if (IS_ERR(req)) + return PTR_ERR(req); + req->end_io_data = &wait; ufshcd_hold(hba, false); Patches currently in stable-queue which might be from jaegeuk@xxxxxxxxxx are queue-5.4/scsi-ufs-fix-tm-request-when-non-fatal-error-happens.patch