Re: [PATCH 4/8] powerpc/64s: fix POWER9 machine check handler from stop state

On Fri, 17 Mar 2017 12:49:27 +1000
Nicholas Piggin [off-list ref] wrote:

On Thu, 16 Mar 2017 18:10:48 +0530
Mahesh Jagannath Salgaonkar [off-list ref] wrote:

quoted

On 03/14/2017 02:53 PM, Nicholas Piggin wrote:  

quoted

Looks like we are not winding up.. Shouldn't we ? What if we may end up
in pnv_wakeup_noloss() which assumes that no GPRs are lost. Am I missing
anything ?  

Hmm, on second look, I don't think any non-volatile GPRs are overwritten
in this path. But this MCE is a slow path, and it is a much longer path
than the system reset idle wakeup... So I'll add the napstatelost with
a comment.

On third look, I'll just add the comment. The windup does not restore
non-volatile GPRs either, and in general we're careful not to use them
in exception handlers. So I think it's okay.

Thanks,
Nick