[PATCH 05/13] powerpc/mce: Allow notifier callback to handle MCE

[Reza Arbab]

Hi Mahesh,

On Fri, Jun 21, 2019 at 12:35:08PM +0530, Mahesh Jagannath Salgaonkar wrote:
>On 6/21/19 6:27 AM, Santosh Sivaraj wrote:
>> -	blocking_notifier_call_chain(&mce_notifier_list, 0, &evt);
>> +	rc = blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
>> +	if (rc & NOTIFY_STOP_MASK) {
>> +		evt->disposition = MCE_DISPOSITION_RECOVERED;
>> +		regs->msr |= MSR_RI;
>
>What is the reason for setting MSR_RI ? I don't think this is a good
>idea. MSR_RI = 0 means system got MCE interrupt when SRR0 and SRR1
>contents were live and was overwritten by MCE interrupt. Hence this
>interrupt is unrecoverable irrespective of whether machine check handler
>recovers from it or not.

Good catch! I think this is an artifact from when I was first trying to 
get all this working.

Instead of setting MSR_RI, we should probably just check for it. Ie,

	if ((rc & NOTIFY_STOP_MASK) && (regs->msr & MSR_RI)) {
		evt->disposition = MCE_DISPOSITION_RECOVERED;

-- 
Reza Arbab