Re: [PATCH v4 2/2] radeon: use memcpy_to/fromio for UVD fw upload

[Christian König <christian.koenig@xxxxxxx>]

Am 04.06.21 um 10:43 schrieb Chen Li:
> I met a gpu addr bug recently and the kernel log
> tells me the pc is memcpy/memset and link register is
> radeon_uvd_resume.
>
> As we know, in some architectures, optimized memcpy/memset
> may not work well on device memory. Trival memcpy_toio/memset_io
> can fix this problem.
>
> BTW, amdgpu has already done it in:
> commit ba0b2275a678 ("drm/amdgpu: use memcpy_to/fromio for UVD fw upload"),
> that's why it has no this issue on the same gpu and platform.
>
> Signed-off-by: Chen Li <chenli@xxxxxxxxxxxxx>
> Reviewed-by: Christian König

Reviewed-by: Christian König <christian.koenig@xxxxxxx>

Alex will probably now pick them up for upstreaming.

Christian.

> ---
>   drivers/gpu/drm/radeon/radeon_uvd.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_uvd.c b/drivers/gpu/drm/radeon/radeon_uvd.c
> index 85a1f2c31749..753da95e6abb 100644
> --- a/drivers/gpu/drm/radeon/radeon_uvd.c
> +++ b/drivers/gpu/drm/radeon/radeon_uvd.c
> @@ -288,7 +288,7 @@ int radeon_uvd_resume(struct radeon_device *rdev)
>   	if (rdev->uvd.vcpu_bo == NULL)
>   		return -EINVAL;
>   
> -	memcpy(rdev->uvd.cpu_addr, rdev->uvd_fw->data, rdev->uvd_fw->size);
> +	memcpy_toio((void __iomem *)rdev->uvd.cpu_addr, rdev->uvd_fw->data, rdev->uvd_fw->size);
>   
>   	size = radeon_bo_size(rdev->uvd.vcpu_bo);
>   	size -= rdev->uvd_fw->size;
> @@ -296,7 +296,7 @@ int radeon_uvd_resume(struct radeon_device *rdev)
>   	ptr = rdev->uvd.cpu_addr;
>   	ptr += rdev->uvd_fw->size;
>   
> -	memset(ptr, 0, size);
> +	memset_io((void __iomem *)ptr, 0, size);
>   
>   	return 0;
>   }