[PATCH] drm/amdgpu: don't put MQDs in VRAM on ARM | ARM64

[Alexey Klimov]

On Tue, 31 Oct 2023 at 17:55, Alex Deucher <alexander.deucher at amd.com> wrote:
>
> Issues were reported with commit 1cfb4d612127
> ("drm/amdgpu: put MQDs in VRAM") on an ADLINK Ampere
> Altra Developer Platform (AVA developer platform).
>
> Various ARM systems seem to have problems related
> to PCIe and MMIO access.  In this case, I'm not sure
> if this is specific to the ADLINK platform or ARM
> in general.  Seems to be some coherency issue with
> VRAM.  For now, just don't put MQDs in VRAM on ARM.
>
> Link: https://lists.freedesktop.org/archives/amd-gfx/2023-October/100453.html
> Fixes: 1cfb4d612127 ("drm/amdgpu: put MQDs in VRAM")
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> Cc: alexey.klimov at linaro.org

Thanks for the patch! Can you please give me day or two to test it a
little bit more? I am still trying ti figure out if page faults in GPU
depend on this patch or not. I can provide Tested-by tag then.

Also, FWIW maybe you can add Reported-by tag.

Thanks,
Alexey


> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> index c92e0aba69e1..a2a29dcb2422 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> @@ -385,9 +385,11 @@ int amdgpu_gfx_mqd_sw_init(struct amdgpu_device *adev,
>         struct amdgpu_ring *ring = &kiq->ring;
>         u32 domain = AMDGPU_GEM_DOMAIN_GTT;
>
> +#if !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
>         /* Only enable on gfx10 and 11 for now to avoid changing behavior on older chips */
>         if (amdgpu_ip_version(adev, GC_HWIP, 0) >= IP_VERSION(10, 0, 0))
>                 domain |= AMDGPU_GEM_DOMAIN_VRAM;
> +#endif
>
>         /* create MQD for KIQ */
>         if (!adev->enable_mes_kiq && !ring->mqd_obj) {
> --
> 2.41.0
>