Re: [PATCH] drm/amdgpu: Fix default page access routing

["Christian König" <deathsimple@vodafone.de>]

On 05.11.2015 20:06, Jay Cornwall wrote:
> The VM default page (used when a VM translation fails) is allocated in
> system memory. The VM is misconfigured to interpret the physical address
> as referencing a VRAM physical page.
>
> Route default page accesses to system memory.
>
> Signed-off-by: Jay Cornwall <jay@jcornwall.me>
> Cc: <stable@vger.kernel.org> # v4.2+

Nice catch, patch is Reviewed-by: Christian König <christian.koenig@amd.com>

Do we also need this for Radeon?

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 1 +
>   drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 1 +
>   2 files changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> index fab5471..b9836f6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> @@ -474,6 +474,7 @@ static int gmc_v7_0_gart_enable(struct amdgpu_device *adev)
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, ENABLE_L2_PDE0_CACHE_LRU_UPDATE_BY_WRITE, 1);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, EFFECTIVE_L2_QUEUE_SIZE, 7);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, CONTEXT1_IDENTITY_ACCESS_MODE, 1);
> +	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, ENABLE_DEFAULT_PAGE_OUT_TO_SYSTEM_MEMORY, 1);
>   	WREG32(mmVM_L2_CNTL, tmp);
>   	tmp = REG_SET_FIELD(0, VM_L2_CNTL2, INVALIDATE_ALL_L1_TLBS, 1);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL2, INVALIDATE_L2_CACHE, 1);
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> index 7bc9e9f..cb4e2bb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> @@ -588,6 +588,7 @@ static int gmc_v8_0_gart_enable(struct amdgpu_device *adev)
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, ENABLE_L2_PDE0_CACHE_LRU_UPDATE_BY_WRITE, 1);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, EFFECTIVE_L2_QUEUE_SIZE, 7);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, CONTEXT1_IDENTITY_ACCESS_MODE, 1);
> +	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, ENABLE_DEFAULT_PAGE_OUT_TO_SYSTEM_MEMORY, 1);
>   	WREG32(mmVM_L2_CNTL, tmp);
>   	tmp = RREG32(mmVM_L2_CNTL2);
>   	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL2, INVALIDATE_ALL_L1_TLBS, 1);