Re: [PATCH v7 7/8] scsi: ufs: Move dumps in IRQ handler to error handler

[Can Guo]

Hi Asutosh,

On 2020-07-29 02:06, Asutosh Das (asd) wrote:

On 7/27/2020 10:00 PM, Can Guo wrote:

Sometime dumps in IRQ handler are heavy enough to cause system stability

issues, move them to error handler.

Signed-off-by: Can Guo <c...@codeaurora.org>
---
  drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++----------------
  1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c480823..b2bafa3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c

@@ -5682,6 +5682,21 @@ static void ufshcd_err_handler(struct work_struct *work)

                                    UFSHCD_UIC_DL_TCx_REPLAY_ERROR))))
                needs_reset = true;
  +     if (hba->saved_err & (INT_FATAL_ERRORS | UIC_ERROR |
+                             UFSHCD_UIC_HIBERN8_MASK)) {
+               bool pr_prdt = !!(hba->saved_err & SYSTEM_BUS_FATAL_ERROR);
+
+               dev_err(hba->dev, "%s: saved_err 0x%x saved_uic_err 0x%x\n",
+                               __func__, hba->saved_err, hba->saved_uic_err);
+               spin_unlock_irqrestore(hba->host->host_lock, flags);
+               ufshcd_print_host_state(hba);
+               ufshcd_print_pwr_info(hba);
+               ufshcd_print_host_regs(hba);
+               ufshcd_print_tmrs(hba, hba->outstanding_tasks);
+               ufshcd_print_trs(hba, hba->outstanding_reqs, pr_prdt);
+               spin_lock_irqsave(hba->host->host_lock, flags);
+       }
+
        /*
         * if host reset is required then skip clearing the pending
         * transfers forcefully because they will get cleared during

@@ -5900,22 +5915,6 @@ static irqreturn_t ufshcd_check_errors(struct ufs_hba *hba)

                /* block commands from scsi mid-layer */
                ufshcd_scsi_block_requests(hba);
-
-               /* dump controller state before resetting */
-               if (hba->saved_err & (INT_FATAL_ERRORS | UIC_ERROR)) {
-                       bool pr_prdt = !!(hba->saved_err &
-                                       SYSTEM_BUS_FATAL_ERROR);
-
-                       dev_err(hba->dev, "%s: saved_err 0x%x saved_uic_err 
0x%x\n",
-                                       __func__, hba->saved_err,
-                                       hba->saved_uic_err);
-
-                       ufshcd_print_host_regs(hba);
-                       ufshcd_print_pwr_info(hba);

How about keep the above prints and move the tmrs and trs to eh?
Sometimes in system instability, the eh may not get a chance to run
even. Still the above prints would provide some clues.

Here is the IRQ handler, ufshcd_print_host_regs() is sometime heavy
enough to cause stability issues during my fault injection test, since
it prints host regs, reg's history, crypto debug infos plus prints
from vops_dump.

How about just printing host regs and reg history here? Most time, these
infos are enough.

Thanks,

Can Guo.

-                       ufshcd_print_tmrs(hba, hba->outstanding_tasks);
-                       ufshcd_print_trs(hba, hba->outstanding_reqs,
-                                       pr_prdt);
-               }
                ufshcd_schedule_eh_work(hba);
                retval |= IRQ_HANDLED;
        }