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

[Limonciello, Mario]

[Public]



> -----Original Message-----
> From: Gong, Richard <Richard.Gong@xxxxxxx>
> Sent: Friday, April 8, 2022 11:20
> To: Limonciello, Mario <Mario.Limonciello@xxxxxxx>; 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
> Subject: Re: [PATCH] drm/amdgpu: disable ASPM for legacy products that
> don't support ASPM
> 
> 
> 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.
> 

Right but what if some other "working" cards are included in the system too?
Then ASPM gets disabled for them too.  It should only be disabled for the pci_dev
corresponding to problematic GPUs in problematic situations.

> > 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