[PATCH] drm/amdgpu: fix the memory corruption on S3

[Michel Dänzer]

On 29/06/17 04:03 PM, Huang Rui wrote:
> psp->cmd will be used on resume phase, so we can not free it on hw_init.
> Otherwise, a memory corruption will be triggered.
> 
> Signed-off-by: Huang Rui <ray.huang at amd.com>
> ---
> 
> Alex, Christian,
> 
> This is the final fix for vega10 S3. The random memory corruption issue is root
> caused.
> 
> Thanks,
> Ray
> 
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> index 5041073..fcdd542 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> @@ -372,8 +372,6 @@ static int psp_load_fw(struct amdgpu_device *adev)
>  	if (ret)
>  		goto failed_mem;
>  
> -	kfree(cmd);
> -
>  	return 0;

This looks like a good catch.


> @@ -384,6 +382,7 @@ static int psp_load_fw(struct amdgpu_device *adev)
>  			      &psp->fw_pri_mc_addr, &psp->fw_pri_buf);
>  failed:
>  	kfree(cmd);
> +	cmd = NULL;

This should probably be

	psp->cmd = NULL;

instead?


> @@ -443,6 +442,11 @@ static int psp_hw_fini(void *handle)
>  		amdgpu_bo_free_kernel(&psp->fence_buf_bo,
>  				      &psp->fence_buf_mc_addr, &psp->fence_buf);
>  
> +	if (!psp->cmd) {
> +		kfree(psp->cmd);
> +		psp->cmd = NULL;
> +	}

This should probably be

	if (psp->cmd) {

? If so, you could skip the if altogether, since kfree(NULL) is safe.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer