linux-kernel - Re: [PATCH v2 2/7] EDAC/amd64: Recognize DRAM device type with EDAC_CTL

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Message-ID: <20190802074224.GB30661@zn.tnic>
Date:   Fri, 2 Aug 2019 09:42:24 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Ghannam, Yazen" <Yazen.Ghannam@....com>
Cc:     "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/7] EDAC/amd64: Recognize DRAM device type with
 EDAC_CTL_CAP

On Tue, Jul 09, 2019 at 09:56:55PM +0000, Ghannam, Yazen wrote:
> From: Yazen Ghannam <yazen.ghannam@....com>
> 
> AMD Family 17h systems support x4 and x16 DRAM devices. However, the
> device type is not checked when setting EDAC_CTL_CAP.
> 
> Set the appropriate EDAC_CTL_CAP flag based on the device type.
> 
> Fixes: 2d09d8f301f5 ("EDAC, amd64: Determine EDAC MC capabilities on Fam17h")

This is better: a patch which fixes a previous patch and is simple,
small and clear. That you can tag with Fixes: just fine.

> Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
> ---
> Link:
> https://lkml.kernel.org/r/20190531234501.32826-4-Yazen.Ghannam@amd.com
> 
> v1->v2:
> * No change.
> 
>  drivers/edac/amd64_edac.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
> index dd60cf5a3d96..125d6e2a828e 100644
> --- a/drivers/edac/amd64_edac.c
> +++ b/drivers/edac/amd64_edac.c
> @@ -3150,12 +3150,15 @@ static bool ecc_enabled(struct pci_dev *F3, u16 nid)
>  static inline void
>  f17h_determine_edac_ctl_cap(struct mem_ctl_info *mci, struct amd64_pvt *pvt)
>  {
> -	u8 i, ecc_en = 1, cpk_en = 1;
> +	u8 i, ecc_en = 1, cpk_en = 1, dev_x4 = 1, dev_x16 = 1;
>  
>  	for_each_umc(i) {
>  		if (pvt->umc[i].sdp_ctrl & UMC_SDP_INIT) {
>  			ecc_en &= !!(pvt->umc[i].umc_cap_hi & UMC_ECC_ENABLED);
>  			cpk_en &= !!(pvt->umc[i].umc_cap_hi & UMC_ECC_CHIPKILL_CAP);
> +
> +			dev_x4 &= !!(pvt->umc[i].dimm_cfg & BIT(6));
> +			dev_x16 &= !!(pvt->umc[i].dimm_cfg & BIT(7));

Are those bits mutually exclusive?

I.e., so that you can do:

	if (dev_x4)
		mci->edac_ctl_cap |= EDAC_FLAG_S4ECD4ED;
	else
		mci->edac_ctl_cap |= EDAC_FLAG_S16ECD16ED;

?

-- 
Regards/Gruss,
    Boris.

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