Re: [PATCHv3] drm/amdgpu: disable ASPM on Intel Alder Lake based systems

[Alex Deucher]

On Tue, Apr 12, 2022 at 10:59 AM Richard Gong <richard.gong@xxxxxxx> 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 won't work
> with ASPM-enabled Intel Alder Lake based systems. Using these GFX cards as
> video/display output, Intel Alder Lake based systems will hang during
> suspend/resume.
>
> The issue was initially reported on one system (Dell Precision 3660 with
> BIOS version 0.14.81), but was later confirmed to affect at least 4 Alder
> Lake based systems.
>
> Add extra check to disable ASPM on Intel Alder Lake based systems.
>
> Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Richard Gong <richard.gong@xxxxxxx>
> ---
> v3: s/intel_core_asom_chk/aspm_support_quirk_check
>     correct build error with W=1 option
> 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..b0b6353b48b9 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)

Shouldn't this be X86?  You could theoretically run this on 32 bit.

Alex

> +#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 aspm_support_quirk_check(void)
> +{
> +       if (IS_ENABLED(CONFIG_X86_64)) {
> +               struct cpuinfo_x86 *c = &cpu_data(0);
> +
> +               return (c->x86 == 6 && c->x86_model != INTEL_FAM6_ALDERLAKE);
> +       }
> +
> +       return true;
> +}
> +
>  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) || !aspm_support_quirk_check())
>                 return;
>
>         if (adev->flags & AMD_IS_APU ||
> --
> 2.25.1
>