RE: [PATCH] drm/amd/pm: fix error handling

[Quan, Evan]

[AMD Official Use Only]

Reviewed-by: Evan Quan <evan.quan@xxxxxxx>

> -----Original Message-----
> From: trix@xxxxxxxxxx <trix@xxxxxxxxxx>
> Sent: Saturday, February 5, 2022 11:00 PM
> To: Quan, Evan <Evan.Quan@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> <Christian.Koenig@xxxxxxx>; Pan, Xinhui <Xinhui.Pan@xxxxxxx>;
> airlied@xxxxxxxx; daniel@xxxxxxxx; nathan@xxxxxxxxxx;
> ndesaulniers@xxxxxxxxxx; Lazar, Lijo <Lijo.Lazar@xxxxxxx>; Powell, Darren
> <Darren.Powell@xxxxxxx>; Chen, Guchun <Guchun.Chen@xxxxxxx>;
> Grodzovsky, Andrey <Andrey.Grodzovsky@xxxxxxx>
> Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; llvm@xxxxxxxxxxxxxxx; Tom Rix <trix@xxxxxxxxxx>
> Subject: [PATCH] drm/amd/pm: fix error handling
> 
> From: Tom Rix <trix@xxxxxxxxxx>
> 
> clang static analysis reports this error
> amdgpu_smu.c:2289:9: warning: Called function pointer
>   is null (null dereference)
>         return smu->ppt_funcs->emit_clk_levels(
>                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> There is a logic error in the earlier check of
> emit_clk_levels.  The error value is set to
> the ret variable but ret is never used.  Return
> directly and remove the unneeded ret variable.
> 
> Fixes: 5d64f9bbb628 ("amdgpu/pm: Implement new API function "emit" that
> accepts buffer base and write offset")
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index af368aa1fd0ae..5f3b3745a9b7a 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -2274,7 +2274,6 @@ static int smu_emit_ppclk_levels(void *handle,
> enum pp_clock_type type, char *bu
>  {
>  	struct smu_context *smu = handle;
>  	enum smu_clk_type clk_type;
> -	int ret = 0;
> 
>  	clk_type = smu_convert_to_smuclk(type);
>  	if (clk_type == SMU_CLK_COUNT)
> @@ -2284,7 +2283,7 @@ static int smu_emit_ppclk_levels(void *handle,
> enum pp_clock_type type, char *bu
>  		return -EOPNOTSUPP;
> 
>  	if (!smu->ppt_funcs->emit_clk_levels)
> -		ret = -ENOENT;
> +		return -ENOENT;
> 
>  	return smu->ppt_funcs->emit_clk_levels(smu, clk_type, buf, offset);
> 
> --
> 2.26.3