Subject: Re: [PATCH] powerpc/eeh: Dump PHB3 diag-data on frozen PE

From: Gavin Shan <[email-masked]>
Date: Wed, 20 Nov 2013 18:09:27 +0800

On Wed, Nov 20, 2013 at 08:38:48PM +1100, Benjamin Herrenschmidt wrote:
>On Wed, 2013-11-20 at 17:36 +0800, Gavin Shan wrote:
>> While we detect frozen PE on PHB3, it's always meaningful to have
>> the dumped diag-data for further diagnosis and analysis.
>
>Don't we trip that during PCI probing ? For example if we probe behind
>a PCI-X bridge (which can exist on an adapter) we'll trip EEH on every
>non-existing device won't we ?
>

Yes, we already had the dumped PHB diag-data when detecting frozen PE
during PCI probing. After PCI probing is completed, the EEH takes over
and we won't dump PHB diag-data during PCI config cycles.

Took a close look on what we have in the code. Those functions to dump
PHB (P7IOC & PHB3) needs a bit rework or refactoring since we're dumping
same PHB diag-data in pci.c and eeh-ioda.c at the same time.

Besides, I think the appropriate place to dump PHB diag-data (for EEH
core itself) would be ioda_eeh_get_log(), which is the indirect backend
of eeh_ops::get_log, instead of the function ioda_eeh_next_error().

Ben, please drop this one for now and I'll send the revised one :-)

Thanks,
Gavin

>> Signed-off-by: Gavin Shan <[email-masked]>
>> ---
>>  arch/powerpc/platforms/powernv/eeh-ioda.c |    3 +++
>>  1 file changed, 3 insertions(+)
>> 
>> diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
>> index 02245ce..481528d 100644
>> --- a/arch/powerpc/platforms/powernv/eeh-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
>> @@ -994,8 +994,11 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
>>  			if (ioda_eeh_get_pe(hose, frozen_pe_no, pe))
>>  				break;
>>  
>> +			/* It would be always indicative to have PHB diag-data */
>>  			pr_err("EEH: Frozen PE#%x on PHB#%x detected\n",
>>  				(*pe)->addr, (*pe)->phb->global_number);
>> +			ioda_eeh_phb_diag(hose);
>> +
>>  			ret = 1;
>>  			goto out;
>>  		}
>
>