uninitialized variable in dcn10 code

[michel@xxxxxxxxxxx (Michel Dänzer)]

On 14/11/17 01:29 PM, Tom St Denis wrote:
> Hi Harry,
> 
> At display/dc/dcn10/dcn10_hw_sequencer.c:2140
> 
> Â Â Â Â if (num_planes > 0) {
> Â Â Â Â Â Â Â  struct dc_stream_state *stream_for_cursor;
> 
> Â Â Â Â Â Â Â  program_all_pipe_in_tree(dc, top_pipe_to_program, context);
> 
> Â Â Â Â Â Â Â  for (i = 0; i < dc->res_pool->pipe_count; i++) {
> Â Â Â Â Â Â Â Â Â Â Â  struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[i];
> 
> Â Â Â Â Â Â Â Â Â Â Â  if (stream == pipe_ctx->stream) {
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  stream_for_cursor = pipe_ctx->stream;
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  break;
> Â Â Â Â Â Â Â Â Â Â Â  }
> Â Â Â Â Â Â Â  }
> 
> Â Â Â Â Â Â Â  /* TODO: this is a hack w/a for switching from mpo to pipe split */
> Â Â Â Â Â Â Â  if (stream_for_cursor->cursor_attributes.address.quad_part != 0) {
> Â Â Â Â Â Â Â Â Â Â Â  struct dc_cursor_position position = { 0 };
> 
> Â Â Â Â Â Â Â Â Â Â Â  dc_stream_set_cursor_position(stream_for_cursor, &position);
> Â Â Â Â Â Â Â Â Â Â Â  dc_stream_set_cursor_attributes(stream_for_cursor,
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  &stream_for_cursor->cursor_attributes);
> Â Â Â Â Â Â Â  }
> Â Â Â Â }
> 
> The variable "stream_for_cursor" could be used uninitialized in the TODO
> block.  The pointer should be probably initialized to NULL at the top.

BTW, the compiler points this out:

drivers/gpu/drm//amd/amdgpu/../display/dc/dcn10/dcn10_hw_sequencer.c: In function â??dcn10_apply_ctx_for_surfaceâ??:
drivers/gpu/drm//amd/amdgpu/../display/dc/dcn10/dcn10_hw_sequencer.c:2146:5: warning: â??stream_for_cursorâ?? may be used uninitialized in this function [-Wmaybe-uninitialized]
     &stream_for_cursor->cursor_attributes);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


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