Re: [PATCH v2] drm/amdgpu: skipping SDMA hw_init and hw_fini for S0ix.

[Alex Deucher <alexdeucher@gmail.com>]

On Thu, Feb 10, 2022 at 10:42 AM Limonciello, Mario
<Mario.Limonciello@amd.com> wrote:
>
> [Public]
>
>
>
> > -----Original Message-----
> > From: Alex Deucher <alexdeucher@gmail.com>
> > Sent: Thursday, February 10, 2022 09:28
> > To: Limonciello, Mario <Mario.Limonciello@amd.com>
> > Cc: Mahapatra, Rajib <Rajib.Mahapatra@amd.com>; Liang, Prike
> > <Prike.Liang@amd.com>; Deucher, Alexander <Alexander.Deucher@amd.com>;
> > amd-gfx@lists.freedesktop.org; S, Shirish <Shirish.S@amd.com>
> > Subject: Re: [PATCH v2] drm/amdgpu: skipping SDMA hw_init and hw_fini for
> > S0ix.
> >
> > On Thu, Feb 10, 2022 at 9:04 AM Limonciello, Mario
> > <Mario.Limonciello@amd.com> wrote:
> > >
> > > [Public]
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Mahapatra, Rajib <Rajib.Mahapatra@amd.com>
> > > > Sent: Thursday, February 10, 2022 07:35
> > > > To: Liang, Prike <Prike.Liang@amd.com>; Limonciello, Mario
> > > > <Mario.Limonciello@amd.com>; Deucher, Alexander
> > > > <Alexander.Deucher@amd.com>
> > > > Cc: amd-gfx@lists.freedesktop.org; S, Shirish <Shirish.S@amd.com>;
> > > > Mahapatra, Rajib <Rajib.Mahapatra@amd.com>
> > > > Subject: [PATCH v2] drm/amdgpu: skipping SDMA hw_init and hw_fini for
> > S0ix.
> > > >
> > > > [Why]
> > > > SDMA ring buffer test failed if suspend is aborted during
> > > > S0i3 resume.
> > > >
> > > > [How]
> > > > If suspend is aborted for some reason during S0i3 resume
> > > > cycle, it follows SDMA ring test failing and errors in amdgpu
> > > > resume. For RN/CZN/Picasso, SMU saves and restores SDMA
> > > > registers during S0ix cycle. So, skipping SDMA suspend and
> > > > resume from driver solves the issue. This time, the system
> > > > is able to resume gracefully even the suspend is aborted.
> > > >
> > > > v2: add changes on sdma_v4, skipping SDMA hw_init and hw_fini.
> > >
> > > This line in the commit message should be "below" the ---
> > >
> > > Besides that the code is better.
> > >
> > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> >
> > Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
> >
> > I presume sdma_v5.2.c needs a similar fix?
>
> VG doesn't do s0i3 right?

Right.

> No, YC should not take a similar fix.    YC had an architectural change and to
> avoid a "similar" problem takes 26db706a6d77b9e184feb11725e97e53b7a89519.

Isn't that likely just a workaround for the same issue?  This seems cleaner.

Alex

>
> >
> > Alex
> >
> >
> > >
> > > > Signed-off-by: Rajib Mahapatra <rajib.mahapatra@amd.com>
> > > > ---
> > > >  drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 8 ++++++++
> > > >  1 file changed, 8 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> > > > b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> > > > index 06a7ceda4c87..02115d63b071 100644
> > > > --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> > > > +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> > > > @@ -2058,6 +2058,10 @@ static int sdma_v4_0_suspend(void *handle)
> > > >  {
> > > >       struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> > > >
> > > > +     /* SMU saves SDMA state for us */
> > > > +     if (adev->in_s0ix)
> > > > +             return 0;
> > > > +
> > > >       return sdma_v4_0_hw_fini(adev);
> > > >  }
> > > >
> > > > @@ -2065,6 +2069,10 @@ static int sdma_v4_0_resume(void *handle)
> > > >  {
> > > >       struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> > > >
> > > > +     /* SMU restores SDMA state for us */
> > > > +     if (adev->in_s0ix)
> > > > +             return 0;
> > > > +
> > > >       return sdma_v4_0_hw_init(adev);
> > > >  }
> > > >
> > > > --
> > > > 2.25.1