Re: [PATCHv2] drm/amdgpu: disable ASPM on Intel AlderLake based systems

[Gong, Richard]

Hi Lijo,

On 4/10/2022 11:15 PM, Lazar, Lijo wrote:
> On 4/9/2022 12:35 AM, Richard Gong wrote:
> > Active State Power Management (ASPM) feature is enabled since kernel 
> > 5.14.
> > There are some AMD GFX cards (such as WX3200 and RX640) that cannot be
> > used with Intel AlderLake based systems to enable ASPM. Using these GFX
> > cards as video/display output, Intel Alder Lake based systems will hang
> > during suspend/resume.
> >
> > Add extra check to disable ASPM on Intel AlderLake based systems.
> >
> > Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
> > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
> > Signed-off-by: Richard Gong <richard.gong@xxxxxxx>
> > ---
> > v2: correct commit description
> >      move the check from chip family to problematic platform
> > ---
> >   drivers/gpu/drm/amd/amdgpu/vi.c | 17 ++++++++++++++++-
> >   1 file changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c 
> > b/drivers/gpu/drm/amd/amdgpu/vi.c
> > index 039b90cdc3bc..8b4eaf54b23e 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/vi.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/vi.c
> > @@ -81,6 +81,10 @@
> >   #include "mxgpu_vi.h"
> >   #include "amdgpu_dm.h"
> >   +#if IS_ENABLED(CONFIG_X86_64)
> > +#include <asm/intel-family.h>
> > +#endif
> > +
> >   #define ixPCIE_LC_L1_PM_SUBSTATE    0x100100C6
> >   #define PCIE_LC_L1_PM_SUBSTATE__LC_L1_SUBSTATES_OVERRIDE_EN_MASK 
> > 0x00000001L
> >   #define PCIE_LC_L1_PM_SUBSTATE__LC_PCI_PM_L1_2_OVERRIDE_MASK 
> > 0x00000002L
> > @@ -1134,13 +1138,24 @@ static void vi_enable_aspm(struct 
> > amdgpu_device *adev)
> >           WREG32_PCIE(ixPCIE_LC_CNTL, data);
> >   }
> >   +static bool intel_core_apsm_chk(void)
>
> If this is only for Dell systems, use DMI_SYS_VENDOR/DMI_PRODUCT_NAME 
> to identify the platform information from SMBIOS.
Not sure, the report issue was originally for Dell system but may occur 
with others. This is why I just check CPU info.
> Better to rename to aspm_support_quirk_check() or similar, and return 
> false on is_alderlake() or is_dell_xyz();
Ok, will rename to aspm_support_quick_check in the next versin.

> Thanks,
> Lijo
>
> > +{
> > +#if IS_ENABLED(CONFIG_X86_64)
> > +    struct cpuinfo_x86 *c = &cpu_data(0);
> > +
> > +    return (c->x86 == 6 && c->x86_model == INTEL_FAM6_ALDERLAKE);
> > +#else
> > +    return false;
> > +#endif
> > +}
> > +
> >   static void vi_program_aspm(struct amdgpu_device *adev)
> >   {
> >       u32 data, data1, orig;
> >       bool bL1SS = false;
> >       bool bClkReqSupport = true;
> >   -    if (!amdgpu_device_should_use_aspm(adev))
> > +    if (!amdgpu_device_should_use_aspm(adev) || intel_core_apsm_chk())
> >           return;
> >         if (adev->flags & AMD_IS_APU ||