drm/amd/display: Fix NULL pointer dereference for program_lut_mode in dcn401_populate_mcm_luts

This commit introduces a NULL pointer check for
mpc->funcs->program_lut_mode in the dcn401_populate_mcm_luts function.
The previous implementation directly called program_lut_mode without
validating its existence, which could lead to a NULL pointer
dereference.

With this change, the function is now only invoked if
mpc->funcs->program_lut_mode is not NULL

Fixes the below:

drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn401/dcn401_hwseq.c:720 dcn401_populate_mcm_luts()
error: we previously assumed 'mpc->funcs->program_lut_mode' could be null (see line 701)

drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn401/dcn401_hwseq.c
    642 void dcn401_populate_mcm_luts(struct dc *dc,
    643                 struct pipe_ctx *pipe_ctx,
    644                 struct dc_cm2_func_luts mcm_luts,
    645                 bool lut_bank_a)
    646 {
	...
    716                 }
    717                 if (m_lut_params.pwl) {
    718                         if (mpc->funcs->mcm.populate_lut)
    719                                 mpc->funcs->mcm.populate_lut(mpc, m_lut_params, lut_bank_a, mpcc_id);
--> 720                         mpc->funcs->program_lut_mode(mpc, MCM_LUT_SHAPER, MCM_LUT_ENABLE, lut_bank_a, mpcc_id);

Cc: Yihan Zhu <[email protected]>
Cc: Harry Wentland <[email protected]>
Cc: Nicholas Kazlauskas <[email protected]>
Cc: Tom Chung <[email protected]>
Cc: Roman Li <[email protected]>
Cc: Alex Hung <[email protected]>
Cc: Aurabindo Pillai <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Reviewed-by: Yihan Zhu <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions