[PATCH v2 2/2] scsi: ufs: Fix tm request when non-fatal error happens

Orson Zhai
2021-11-18T14:08:01Z

From: Jaegeuk Kim <jaegeuk@kernel.org>

[ Upstream commit eeb1b55b6e25c5f7265ff45cd050f3bc2cc423a4 ]

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@kernel.org
Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs")
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[Zhai: remove an item of debug print not available in v5.4]
Signed-off-by: Orson Zhai <orson.zhai@unisoc.com>
---
drivers/scsi/ufs/ufshcd.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a5d4ee6..29c7a76 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4748,7 +4748,8 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
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, void *__hba)
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 ufs_hba *hba,
/*
* 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);

--
2.7.4