This commit removes an unnecessary NULL check in the
`dcn20_set_input_transfer_func` function in the `dcn20_hwseq.c` file.
The variable `tf` is assigned the address of
`plane_state->in_transfer_func` unconditionally, so it can never be
`NULL`. Therefore, the check `if (tf == NULL)` is unnecessary and has
been removed.
The plane_state->in_transfer_func itself cannot be NULL because it's a
structure, not a pointer. When we do tf =
&plane_state->in_transfer_func;, we're getting the address of that
structure, which will always be valid as long as plane_state itself is
not NULL.
we've already checked if plane_state is NULL with the line if (dpp_base
== NULL || plane_state == NULL) return false;. So, if the code execution
gets to the point where tf = &plane_state->in_transfer_func; is called,
plane_state is guaranteed to be not NULL, and therefore tf will also not
be NULL.
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn20/dcn20_hwseq.c
1094 bool dcn20_set_input_transfer_func(struct dc *dc,
1095 struct pipe_ctx *pipe_ctx,
1096 const struct dc_plane_state *plane_state)
1097 {
1098 struct dce_hwseq *hws = dc->hwseq;
1099 struct dpp *dpp_base = pipe_ctx->plane_res.dpp;
1100 const struct dc_transfer_func *tf = NULL;
^^^^^^^^^ This assignment is not necessary now.
1101 bool result = true;
1102 bool use_degamma_ram = false;
1103
1104 if (dpp_base == NULL || plane_state == NULL)
1105 return false;
1106
1107 hws->funcs.set_shaper_3dlut(pipe_ctx, plane_state);
1108 hws->funcs.set_blend_lut(pipe_ctx, plane_state);
1109
1110 tf = &plane_state->in_transfer_func;
^^^^^
Before there was an if statement but now tf is assigned unconditionally
1111
--> 1112 if (tf == NULL) {
^^^^^^^^^^^^^^^^^
so these conditions are impossible.
1113 dpp_base->funcs->dpp_set_degamma(dpp_base,
1114 IPP_DEGAMMA_MODE_BYPASS);
1115 return true;
1116 }
1117
1118 if (tf->type == TF_TYPE_HWPWL || tf->type == TF_TYPE_DISTRIBUTED_POINTS)
1119 use_degamma_ram = true;
1120
1121 if (use_degamma_ram == true) {
1122 if (tf->type == TF_TYPE_HWPWL)
1123 dpp_base->funcs->dpp_program_degamma_pwl(dpp_base,
Fixes the below Smatch static checker warning:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn20/dcn20_hwseq.c:1112 dcn20_set_input_transfer_func() warn: address of 'plane_state->in_transfer_func' is non-NULL
Fixes: 285a7054bf81 ("drm/amd/display: Remove plane and stream pointers from dc scratch")
Cc: Wenjing Liu <wenjing.liu@xxxxxxx>
Cc: Tom Chung <chiahsuan.chung@xxxxxxx>
Cc: Alvin Lee <alvin.lee2@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Roman Li <roman.li@xxxxxxx>
Cc: Qingqing Zhuo <Qingqing.Zhuo@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c
index b60ba2a110f7..58fbdd535068 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c
@@ -1109,12 +1109,6 @@ bool dcn20_set_input_transfer_func(struct dc *dc,
tf = &plane_state->in_transfer_func;
- if (tf == NULL) {
- dpp_base->funcs->dpp_set_degamma(dpp_base,
- IPP_DEGAMMA_MODE_BYPASS);
- return true;
- }
-
if (tf->type == TF_TYPE_HWPWL || tf->type == TF_TYPE_DISTRIBUTED_POINTS)
use_degamma_ram = true;
--
2.34.1
