From: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@ozlabs.org
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Subject: Re: [PATCH] powerpc/powernv/elog: Reduce elog message severity
Date: Sat, 17 Oct 2020 22:42:16 +0530 [thread overview]
Message-ID: <c616affd-d27f-42a9-11e8-e45ffc5293a6@linux.vnet.ibm.com> (raw)
In-Reply-To: <87d01s0z37.fsf@mpe.ellerman.id.au>
On 10/9/20 10:34 AM, Michael Ellerman wrote:
> Vasant Hegde <hegdevasant@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@linux.ibm.com>
>> Signed-off-by: Vasant Hegde <hegdevasant@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
prev parent reply other threads:[~2020-10-17 17:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 10:17 [PATCH] powerpc/powernv/elog: Reduce elog message severity Vasant Hegde
2020-10-09 5:04 ` Michael Ellerman
2020-10-17 17:12 ` Vasant Hegde [this message]
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