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

[Can Guo <cang@codeaurora.org>]

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@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;
>>   	}
>>