linux-kernel - Re: [PATCH 3/4] EDAC/amd64: Set zn_regs_v2 flag for all AMD Family 1Ah-based SOCs

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Message-ID: <20251030134839.GA3209@yaz-khff2.amd.com>
Date: Thu, 30 Oct 2025 09:48:39 -0400
From: Yazen Ghannam <yazen.ghannam@....com>
To: Borislav Petkov <bp@...en8.de>
Cc: Avadhut Naik <avadhut.naik@....com>, linux-edac@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/4] EDAC/amd64: Set zn_regs_v2 flag for all AMD Family
 1Ah-based SOCs

On Wed, Oct 29, 2025 at 06:10:57PM +0100, Borislav Petkov wrote:
> On Mon, Oct 13, 2025 at 05:30:42PM +0000, Avadhut Naik wrote:

[...]

> > --- a/drivers/edac/amd64_edac.c
> > +++ b/drivers/edac/amd64_edac.c
> > @@ -3779,6 +3779,8 @@ static int per_family_init(struct amd64_pvt *pvt)
> >  	else
> >  		pvt->ops = &dct_ops;
> >  
> > +	pvt->flags.zn_regs_v2 = (pvt->fam >= 0x1A) ? 1 : 0;
> > +
> >  	switch (pvt->fam) {
> >  	case 0xf:
> >  		tmp_name				= (pvt->ext_model >= K8_REV_F) ?
> > @@ -3887,20 +3889,14 @@ static int per_family_init(struct amd64_pvt *pvt)
> >  		switch (pvt->model) {
> >  		case 0x00 ... 0x1f:
> >  			pvt->max_mcs            = 12;
> > -			pvt->flags.zn_regs_v2   = 1;
> > -			break;
> > -		case 0x40 ... 0x4f:
> > -			pvt->flags.zn_regs_v2   = 1;
> >  			break;
> >  		case 0x50 ... 0x57:
> >  		case 0xc0 ... 0xc7:
> >  			pvt->max_mcs            = 16;
> > -			pvt->flags.zn_regs_v2   = 1;
> >  			break;
> >  		case 0x90 ... 0x9f:
> >  		case 0xa0 ... 0xaf:
> >  			pvt->max_mcs            = 8;
> > -			pvt->flags.zn_regs_v2   = 1;
> >  			break;
> >  		}
> 
> I'm not sure about this: if we hoist this particular assignment up, then
> what's the point of the tabellary switch-case where you can see at a quick
> glance, all the settings that we do per model...?
> 

I think we should take any opportunity to get away from family/model
checks.

Yes, we still have one item (max_mcs) left. As a follow up, we can see
if this can be removed also.

Thanks,
Yazen