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

[Asutosh Das (asd)]

On 7/29/2020 6:02 AM, Can Guo wrote:
> 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 <cang@xxxxxxxxxxxxxx>
> > > ---
> > > Â drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++----------------
> > > Â 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)
> > > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ UFSHCD_UIC_DL_TCx_REPLAY_ERROR))))
> > > ÂÂÂÂÂÂÂÂÂ needs_reset = true;
> > > Â +ÂÂÂ if (hba->saved_err & (INT_FATAL_ERRORS | UIC_ERROR |
> > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ UFSHCD_UIC_HIBERN8_MASK)) {
> > > +ÂÂÂÂÂÂÂ bool pr_prdt = !!(hba->saved_err & SYSTEM_BUS_FATAL_ERROR);
> > > +
> > > +ÂÂÂÂÂÂÂ dev_err(hba->dev, "%s: saved_err 0x%x saved_uic_err 0x%x\n",
> > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __func__, hba->saved_err, hba->saved_uic_err);
> > > +ÂÂÂÂÂÂÂ spin_unlock_irqrestore(hba->host->host_lock, flags);
> > > +ÂÂÂÂÂÂÂ ufshcd_print_host_state(hba);
> > > +ÂÂÂÂÂÂÂ ufshcd_print_pwr_info(hba);
> > > +ÂÂÂÂÂÂÂ ufshcd_print_host_regs(hba);
> > > +ÂÂÂÂÂÂÂ ufshcd_print_tmrs(hba, hba->outstanding_tasks);
> > > +ÂÂÂÂÂÂÂ ufshcd_print_trs(hba, hba->outstanding_reqs, pr_prdt);
> > > +ÂÂÂÂÂÂÂ spin_lock_irqsave(hba->host->host_lock, flags);
> > > +ÂÂÂ }
> > > +
> > > ÂÂÂÂÂ /*
> > > ÂÂÂÂÂÂ * if host reset is required then skip clearing the pending
> > > ÂÂÂÂÂÂ * transfers forcefully because they will get cleared during
> > > @@ -5900,22 +5915,6 @@ static irqreturn_t ufshcd_check_errors(struct 
> > > ufs_hba *hba)
> > > ÂÂÂÂÂÂÂÂÂÂÂ /* block commands from scsi mid-layer */
> > > ÂÂÂÂÂÂÂÂÂ ufshcd_scsi_block_requests(hba);
> > > -
> > > -ÂÂÂÂÂÂÂ /* dump controller state before resetting */
> > > -ÂÂÂÂÂÂÂ if (hba->saved_err & (INT_FATAL_ERRORS | UIC_ERROR)) {
> > > -ÂÂÂÂÂÂÂÂÂÂÂ bool pr_prdt = !!(hba->saved_err &
> > > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ SYSTEM_BUS_FATAL_ERROR);
> > > -
> > > -ÂÂÂÂÂÂÂÂÂÂÂ dev_err(hba->dev, "%s: saved_err 0x%x saved_uic_err 
> > > 0x%x\n",
> > > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ __func__, hba->saved_err,
> > > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ hba->saved_uic_err);
> > > -
> > > -ÂÂÂÂÂÂÂÂÂÂÂ ufshcd_print_host_regs(hba);
> > > -ÂÂÂÂÂÂÂÂÂÂÂ 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.
That'd work too.

> Thanks,
>
> Can Guo.
>
> > > -ÂÂÂÂÂÂÂÂÂÂÂ ufshcd_print_tmrs(hba, hba->outstanding_tasks);
> > > -ÂÂÂÂÂÂÂÂÂÂÂ ufshcd_print_trs(hba, hba->outstanding_reqs,
> > > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_prdt);
> > > -ÂÂÂÂÂÂÂ }
> > > ÂÂÂÂÂÂÂÂÂ ufshcd_schedule_eh_work(hba);
> > > ÂÂÂÂÂÂÂÂÂ retval |= IRQ_HANDLED;
> > > ÂÂÂÂÂ }


--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project