[PATCH] drm/amdgpu: disable BAR resize on Dell G5 SE

[Alex Deucher]

On Tue, Feb 18, 2025 at 11:05 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>
>
>
> On 2/18/2025 8:38 PM, Alex Deucher wrote:
> > There was a quirk added to add a workaround for a Sapphire
> > RX 5600 XT Pulse that didn't allow BAR resizing.  However,
> > the quirk casused a regression on Dell laptops using those
> > chips, rather than narrowing the scope of the resizing
> > quirk, add a quirk to prevent amdgpu from resizing the BAR
> > on those Dell platforms.
> >
> > Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/1707
> > Fixes: 907830b0fc9e ("PCI: Add a REBAR size quirk for Sapphire RX 5600 XT Pulse")
> > Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>
> As per the issue thread, issue happens when dGPU resumes from runpm. If
> so, can't we disable runpm as the workaround (IMO, the current patch
> also is a workaround)?

This seems like a better workaround than disabling runtime pm.
Leaving the dGPU powered up all the time seems worse than limiting the
BAR size on this platform.

Alex

>
> Thanks,
> Lijo
>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > index 512e642477a7e..56fd874a22de8 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > @@ -1662,6 +1662,12 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
> >       if (amdgpu_sriov_vf(adev))
> >               return 0;
> >
> > +     /* skip resizing on Dell G5 SE platforms */
> > +     if (adev->pdev->vendor == PCI_VENDOR_ID_ATI &&
> > +         adev->pdev->device == 0x731f &&
> > +         adev->pdev->subsystem_vendor == PCI_VENDOR_ID_DELL)
> > +             return 0;
> > +
> >       /* PCI_EXT_CAP_ID_VNDR extended capability is located at 0x100 */
> >       if (!pci_find_ext_capability(adev->pdev, PCI_EXT_CAP_ID_VNDR))
> >               DRM_WARN("System can't access extended configuration space, please check!!\n");
>