linux-kernel - Re: [PATCH] drm/amdgpu/gfx10: remove redundant repeated null checks

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Message-ID: <CADnq5_Mk3FO_tvxFo+fJgqskVc7qtGv74VM6EStx_BcVpahXEQ@mail.gmail.com>
Date: Mon, 4 Aug 2025 11:08:57 -0400
From: Alex Deucher <alexdeucher@...il.com>
To: Dan Carpenter <dan.carpenter@...aro.org>
Cc: Ethan Carter Edwards <ethan@...ancedwards.com>, Alex Deucher <alexander.deucher@....com>, 
	Christian König <christian.koenig@....com>, 
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, amd-gfx@...ts.freedesktop.org, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
	kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] drm/amdgpu/gfx10: remove redundant repeated null checks

On Mon, Aug 4, 2025 at 10:49 AM Dan Carpenter <dan.carpenter@...aro.org> wrote:
>
> On Mon, Aug 04, 2025 at 10:32:43AM -0400, Alex Deucher wrote:
> > On Sat, Aug 2, 2025 at 4:22 AM Ethan Carter Edwards
> > <ethan@...ancedwards.com> wrote:
> > >
> > > The repeated checks on grbm_soft_reset are unnecessary. Remove them.
> > >
> >
> > These are not NULL checks and they are necessary.  The code is
> > checking if any bits are set in that register.  If not, then we can
> > skip that code as there is nothing to do.
> >
>
> It's not a null check, but it is a nested check and it's a local
> variable so the patch is correct enough.  At this point we know that
> grbm_soft_reset can't be zero.

It can be 0 as far as I can see.  If none of the GRBM_STATUS bits are
set, then we never set any of the bits in grbm_soft_reset.

Alex

>
> regards,
> dan carpenter
>