Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220408190502.4103670-1-richard.gong@amd.com>
In-Reply-To: <20220408190502.4103670-1-richard.gong@amd.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Fri, 8 Apr 2022 15:08:33 -0400
Message-ID: <CADnq5_NY-2sX+5Q7LZWpRqPz0dQg4-xgqSx2_-qzvZ8Ar=J_YA@mail.gmail.com>
Subject: Re: [PATCHv2] drm/amdgpu: disable ASPM on Intel AlderLake 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>,
        "Limonciello, Mario" <mario.limonciello@amd.com>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, Apr 8, 2022 at 3:05 PM Richard Gong <richard.gong@amd.com> 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@amd.com>

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

> ---
> 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 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 ||
> --
> 2.25.1
>