Re: [PATCH 2/2] ARM: errata: add support for A12/A17 errata CR711784
From: Doug Anderson
Date: Tue Apr 23 2019 - 10:38:09 EST
Hi,
On Tue, Apr 23, 2019 at 3:19 AM Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> Hi Doug,
>
> On 19/04/2019 23:18, Douglas Anderson wrote:
> > This adds a code for turning on chicken bit 11, which appears to avoid
> > a potential CPU deadlock that could occur. The exact set of
> > instruction needed to trigger this errata is not totaly known but we
> > have a high level of confidence that the problem is fixed by setting
> > chicken bit 11.
> >
> > All details are in http://crbug.com/711784
> >
> > This erratum has no known number and thus I have tagged it CR711784
> > (after the Chrome OS bug number). I have created separate A12 / A17
> > configs to match how the rest of the A12 / A17 errata is handled.
>
> The written-up workarounds for 85727[12] do actually say to set both
> bits 10 and 11 of the diagnostic register, so you could probably just
> fold this into the first patch and not have to worry about what to call it.
>
> Robin.
Thanks! I was unable to find any official docs here and my past
contacts with ARM about this matter have been silent. All I had was a
preliminary errata description and it only included bit 10.
I'll spin a v2 with them both together then.
-Doug