[PATCH] powerpc/powernv/elog: Reduce elog message severity

[Vasant Hegde]

On 10/9/20 10:34 AM, Michael Ellerman wrote:
> Vasant Hegde <hegdevasant at linux.vnet.ibm.com> writes:
>> OPAL interrupts kernel whenever it has new error log. Kernel calls
>> interrupt handler (elog_event()) to retrieve event. elog_event makes
>> OPAL API call (opal_get_elog_size()) to retrieve elog info.
>>
>> In some case before kernel makes opal_get_elog_size() call, it gets interrupt
>> again. So second time when elog_event() calls opal_get_elog_size API OPAL
>> returns error.
> 
> Can you give more detail there? Do you have a stack trace?

I observe below log in dmesg
   [  615.708709] ELOG: OPAL log info read failed

That means elog_event called twice for same error log event.
I don't have stack trace.

> 
> We use IRQF_ONESHOT for elog_event(), which (I thought) meant it
> shouldn't be called again until it has completed.

Yes. I thought so.. But once in a while we get above message (mostly when we 
have multiple event bits are set).

-Vasant


> 
> So I'm unclear how you're seeing the behaviour you describe.
> 
> cheers
> 
>> Its safe to ignore this error. Hence reduce the severity
>> of log message.
>>
>> CC: Mahesh Salgaonkar <mahesh at linux.ibm.com>
>> Signed-off-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
>> ---
>>   arch/powerpc/platforms/powernv/opal-elog.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/platforms/powernv/opal-elog.c b/arch/powerpc/platforms/powernv/opal-elog.c
>> index 62ef7ad995da..67f435bb1ec4 100644
>> --- a/arch/powerpc/platforms/powernv/opal-elog.c
>> +++ b/arch/powerpc/platforms/powernv/opal-elog.c
>> @@ -247,7 +247,7 @@ static irqreturn_t elog_event(int irq, void *data)
>>   
>>   	rc = opal_get_elog_size(&id, &size, &type);
>>   	if (rc != OPAL_SUCCESS) {
>> -		pr_err("ELOG: OPAL log info read failed\n");
>> +		pr_debug("ELOG: OPAL log info read failed\n");
>>   		return IRQ_HANDLED;
>>   	}
>>   
>> -- 
>> 2.26.2