Re: [PATCH] drm/amdgpu: disable ASPM for legacy products that don't support ASPM

[Gong, Richard]

On 4/8/2022 10:47 AM, Limonciello, Mario wrote:
> [Public]
>
>
>
> > -----Original Message-----
> > From: Gong, Richard <Richard.Gong@xxxxxxx>
> > Sent: Friday, April 8, 2022 10:45
> > To: Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> > <Christian.Koenig@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>;
> > airlied@xxxxxxxx; daniel@xxxxxxxx
> > Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Limonciello, Mario <Mario.Limonciello@xxxxxxx>;
> > Gong, Richard <Richard.Gong@xxxxxxx>
> > Subject: [PATCH] drm/amdgpu: disable ASPM for legacy products that don't
> > support ASPM
> >
> > Active State Power Management (ASPM) feature is enabled since kernel
> > 5.14.
> > However there are some legacy products (WX3200 and RX640 are examples)
> > that
> > do not support ASPM. Use them as video/display output and system would
> > hang
> > during suspend/resume.
> >
> > Add extra check to disable ASPM for old products that don't have
> > ASPM support.
> >
> > Signed-off-by: Richard Gong <richard.gong@xxxxxxx>
> > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > index bb1c025d9001..8987107f41ee 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > @@ -2012,6 +2012,10 @@ static int amdgpu_pci_probe(struct pci_dev
> > *pdev,
> >   	if (amdgpu_aspm == -1 && !pcie_aspm_enabled(pdev))
> >   		amdgpu_aspm = 0;
> >
> > +	/* disable ASPM for the legacy products that don't support ASPM */
> > +	if ((flags & AMD_ASIC_MASK) == CHIP_POLARIS12)
> > +		amdgpu_aspm = 0;
> > +
> I think it's problematic to disable it for the entire driver.  There might be multiple
> AMDGPUs in the system, and others may support ASPM.

The "problem" are WX3200 and RX640, both are from the same POLARIS12 family.

> Can it be done just as part of probe for Polaris?
>
> >   	if (amdgpu_virtual_display ||
> >   	    amdgpu_device_asic_has_dc_support(flags & AMD_ASIC_MASK))
> >   		supports_atomic = true;
> > --
> > 2.25.1