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References: <20220429160604.2608782-1-richard.gong@amd.com>
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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Fri, 29 Apr 2022 12:13:38 -0400
Message-ID: <CADnq5_OoyRmM+tWZ_nipfnNyxFVnyUH+R8Pc4-u2akeffXgssg@mail.gmail.com>
Subject: Re: [PATCHv5] drm/amdgpu: vi: disable ASPM on Intel Alder Lake based systems
To:     Richard Gong <richard.gong@amd.com>
Cc:     "Deucher, Alexander" <alexander.deucher@amd.com>,
        Christian Koenig <christian.koenig@amd.com>,
        xinhui pan <xinhui.pan@amd.com>,
        Dave Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        kernel test robot <lkp@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        "Limonciello, Mario" <mario.limonciello@amd.com>
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Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

On Fri, Apr 29, 2022 at 12:08 PM Richard Gong <richard.gong@amd.com> wrote:
>
> Active State Power Management (ASPM) feature is enabled since kernel 5.14.
> There are some AMD Volcanic Islands (VI) GFX cards, such as the WX3200 and
> RX640, that do not work with ASPM-enabled Intel Alder Lake based systems.
> Using these GFX cards as video/display output, Intel Alder Lake based
> systems will freeze after suspend/resume.
>
> The issue was originally reported on one system (Dell Precision 3660 with
> BIOS version 0.14.81), but was later confirmed to affect at least 4
> pre-production Alder Lake based systems.
>
> Add an extra check to disable ASPM on Intel Alder Lake based systems with
> the problematic AMD Volcanic Islands GFX cards.
>
> Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Richard Gong <richard.gong@amd.com>
> ---
> v5: added vi to commit header and updated commit message
>     rolled back guard with the preprocessor as did in v2 to correct build
>     error on non-x86 systems
> v4: s/CONFIG_X86_64/CONFIG_X86
>     enhanced check logic
> v3: s/intel_core_aspm_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..45f0188c4273 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)
> +#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)
> +       struct cpuinfo_x86 *c = &cpu_data(0);
> +
> +       return !(c->x86 == 6 && c->x86_model == INTEL_FAM6_ALDERLAKE);
> +#else
> +       return true;
> +#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) || !aspm_support_quirk_check())
>                 return;
>
>         if (adev->flags & AMD_IS_APU ||
> --
> 2.25.1
>