scsi: ufs: Fix tm request when non-fatal error happens

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>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index cff4f52..fb32d12 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4994,7 +4994,8 @@ 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;
 }
@@ -6300,9 +6301,13 @@ 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, 0x%08x)\n",
+                                       __func__,
+                                       intr_status,
+                                       hba->ufs_stats.last_intr_status,
+                                       enabled_intr_status);
                ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
        }
 
@@ -6346,7 +6351,10 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
         * Even though we use wait_event() which sleeps indefinitely,
         * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
         */
-       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;
        free_slot = req->tag;
        WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);