[PATCH] drm/amd: Initialize remove_mpcc in dcn201_update_mpcc()

Nathan Chancellor
2021-09-30T16:16:59Z

Clang warns:

drivers/gpu/drm/amd/amdgpu/../display/dc/dcn201/dcn201_hwseq.c:505:6: error: variable 'remove_mpcc' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (mpc->funcs->get_mpcc_for_dpp_from_secondary)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn201/dcn201_hwseq.c:509:6: note: uninitialized use occurs here
if (remove_mpcc != NULL && mpc->funcs->remove_mpcc_from_secondary)
^~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn201/dcn201_hwseq.c:505:2: note: remove the 'if' if its condition is always true
if (mpc->funcs->get_mpcc_for_dpp_from_secondary)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn201/dcn201_hwseq.c:442:26: note: initialize the variable 'remove_mpcc' to silence this warning
struct mpcc *remove_mpcc;
^
= NULL
1 error generated.

The code already handles remove_mpcc being NULL just fine so initialize
it to NULL at the beginning of the function so it is never used
uninitialized.

Fixes: ff7e396f822f ("drm/amd/display: add cyan_skillfish display support")
Link: https://github.com/ClangBuiltLinux/linux/issues/1469
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hwseq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hwseq.c
index ceaaeeb8f2de..cfd09b3f705e 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hwseq.c
@@ -439,7 +439,7 @@ void dcn201_update_mpcc(struct dc *dc, struct pipe_ctx *pipe_ctx)
bool per_pixel_alpha = pipe_ctx->plane_state->per_pixel_alpha && pipe_ctx->bottom_pipe;
int mpcc_id, dpp_id;
struct mpcc *new_mpcc;
- struct mpcc *remove_mpcc;
+ struct mpcc *remove_mpcc = NULL;
struct mpc *mpc = dc->res_pool->mpc;
struct mpc_tree *mpc_tree_params = &(pipe_ctx->stream_res.opp->mpc_tree_params);

base-commit: 30fc33064c846df29888c3c61e30a064aad3a342
--
2.33.0.591.gddb1055343