On Mon, Mar 2, 2020 at 2:43 PM Nathan Chancellor natechancellor@gmail.com wrote:

Clang warns:

drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dmub_psr.c:147:31: warning: address of 'pipe_ctx->plane_res' will always evaluate to 'true' [-Wpointer-bool-conversion] if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res) ~ ~~~~~~~~~~^~~~~~~~~ drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dmub_psr.c:147:56: warning: address of 'pipe_ctx->stream_res' will always evaluate to 'true' [-Wpointer-bool-conversion] if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res) ~ ~~~~~~~~~~^~~~~~~~~~ 2 warnings generated.

As long as pipe_ctx is not NULL, the address of members in this struct cannot be NULL, which means these checks will always evaluate to false.

Fixes: 4c1a1335dfe0 ("drm/amd/display: Driverside changes to support PSR in DMCUB") Link: https://github.com/ClangBuiltLinux/linux/issues/915 Signed-off-by: Nathan Chancellor natechancellor@gmail.com

Indeed, they are not pointers, and no members within `struct plane_resource` or `struct stream_resource` seem to indicate that they are somehow invalid. Good job sleuthing out the correct fixes by tag. Reviewed-by: Nick Desaulniers ndesaulniers@google.com

---

drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c index 2c932c29f1f9..a9e1c01e9d9b 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c @@ -144,7 +144,7 @@ static bool dmub_psr_copy_settings(struct dmub_psr *dmub, } }

•   if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res)
  

•   if (!pipe_ctx)
            return false;
  
    // First, set the psr version
  

-- 2.25.1