linux-kernel - Re: [PATCH v2 06/10] EDAC/ghes: Remove local variable rdr_mask in ghes_edac

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Date:   Mon, 27 Apr 2020 09:08:02 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Robert Richter <rrichter@...vell.com>
Cc:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        Tony Luck <tony.luck@...el.com>,
        James Morse <james.morse@....com>,
        Aristeu Rozanski <aris@...hat.com>,
        Matthias Brugger <mbrugger@...e.com>,
        linux-edac@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 06/10] EDAC/ghes: Remove local variable rdr_mask in
 ghes_edac_dmidecode()

On Wed, Apr 22, 2020 at 01:58:10PM +0200, Robert Richter wrote:
> The local variable rdr_mask serves as a static constant here. It hides
> what the code is doing. Remove it and replace it with the actual logic
> that checks some bits.
> 
> Signed-off-by: Robert Richter <rrichter@...vell.com>
> ---
>  drivers/edac/ghes_edac.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
> index a5890afa9c71..038e560fd332 100644
> --- a/drivers/edac/ghes_edac.c
> +++ b/drivers/edac/ghes_edac.c
> @@ -191,7 +191,6 @@ static void ghes_edac_dmidecode(const struct dmi_header *dh, void *arg)
>  	if (dh->type == DMI_ENTRY_MEM_DEVICE) {
>  		struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
>  		struct dimm_info *dimm = edac_get_dimm(mci, dimm_fill->count, 0, 0);
> -		u16 rdr_mask = BIT(7) | BIT(13);
>  
>  		if (entry->size == 0xffff) {
>  			pr_info("Can't get DIMM%i size\n",
> @@ -241,7 +240,8 @@ static void ghes_edac_dmidecode(const struct dmi_header *dh, void *arg)
>  		default:
>  			if (entry->type_detail & BIT(6))
>  				dimm->mtype = MEM_RMBS;
> -			else if ((entry->type_detail & rdr_mask) == rdr_mask)
> +			else if ((entry->type_detail & BIT(7)) &&
> +				 (entry->type_detail & BIT(13)))

Well, "checks some bits" doesn't make it more telling than checking a
descriptive name like "rdr_mask" but ok, since we're assigning MEM_RDR
here, it is still clear what the check does.

Btw, please write it like this:

			else if (entry->type_detail & (BIT(7) | BIT(13)))

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette