RE: [PATCH v3 0/8] AMD64 EDAC fixes

From: Ghannam, Yazen
Date: Mon Aug 26 2019 - 10:19:25 EST

> -----Original Message-----
> From: linux-edac-owner@xxxxxxxxxxxxxxx <linux-edac-owner@xxxxxxxxxxxxxxx> On Behalf Of Borislav Petkov
> Sent: Friday, August 23, 2019 10:38 AM
> To: Ghannam, Yazen <Yazen.Ghannam@xxxxxxx>
> Cc: Adam Borowski <kilobyte@xxxxxxxxxx>; linux-edac@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 0/8] AMD64 EDAC fixes
> On Fri, Aug 23, 2019 at 03:28:59PM +0000, Ghannam, Yazen wrote:
> > Boris, Do you think it'd be appropriate to change the return values
> > for some cases?
> >
> > For example, ECC disabled is a hardware configuration. This doesn't
> > mean that the module failed any operations in this case.
> >
> > In other words, the module checks for a feature. If the feature is not
> > present, then return without failure (and maybe give a message).
> That makes sense but AFAICT if probe_one_instance() sees that ECC is not
> enabled, it returns 0.
> The "if (!edac_has_mcs())" check later is to verify that at least once
> instance was loaded successfully and, if not, then return an error.
> So where does it return failure?

I was tracking down the failure with ECC disabled, and that seems to be it.

So I think we should return 0 "if (!edac_has_mcs())", because we'd only get
there if ECC is disabled on all nodes and there wasn't some other initialization

I'll send a patch for this soon.

Adam, would you mind testing this patch?