On 6/10/25 00:10, Markus Elfring wrote:
From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Tue, 10 Jun 2025 07:42:40 +0200
The label “cleanup” was used to jump to another pointer check despite of
the detail in the implementation of the function
“dm_validate_stream_and_context”
that it was determined already that corresponding variables contained
still null pointers.
1. Thus return directly if
* a null pointer was passed for the function parameter “stream”
or
* a call of the function “dc_create_plane_state” failed.
2. Use a more appropriate label instead.
3. Delete two questionable checks.
4. Omit extra initialisations (for the variables “dc_state” and
“dc_plane_state”)
which became unnecessary with this refactoring.
This issue was detected by using the Coccinelle software.
Reported-by: kernel test robot <l...@intel.com>
Closes:
https://lore.kernel.org/oe-kbuild-all/202506100312.ms4xgazw-...@intel.com/
Fixes: 5468c36d6285 ("drm/amd/display: Filter Invalid 420 Modes for HDMI TMDS")
Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
V3:
* Another function call was renamed.
* Recipient lists were adjusted once more.
V2:
* The change suggestion was rebased on source files of
the software “Linux next-20250606”.
* Recipient lists were adjusted accordingly.
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 20 ++++++++-----------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 78816712afbb..7dc80b2fbd30 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7473,19 +7473,19 @@ static enum dc_status
dm_validate_stream_and_context(struct dc *dc,
struct dc_stream_state *stream)
{
enum dc_status dc_result = DC_ERROR_UNEXPECTED;
- struct dc_plane_state *dc_plane_state = NULL;
- struct dc_state *dc_state = NULL;
+ struct dc_plane_state *dc_plane_state;
+ struct dc_state *dc_state;
if (!stream)
- goto cleanup;
+ return dc_result;
dc_plane_state = dc_create_plane_state(dc);
if (!dc_plane_state)
- goto cleanup;
+ return dc_result;
I think the two early returns look fine, but the rest of the changes
reduces the readability and reusability.
dc_state = dc_state_create(dc, NULL);
if (!dc_state)
- goto cleanup;
+ goto release_plane_state;
/* populate stream to plane */
dc_plane_state->src_rect.height = stream->src.height;
@@ -7522,13 +7522,9 @@ static enum dc_status
dm_validate_stream_and_context(struct dc *dc,
if (dc_result == DC_OK)
dc_result = dc_validate_global_state(dc, dc_state,
DC_VALIDATE_MODE_ONLY);
-cleanup:
- if (dc_state)
- dc_state_release(dc_state);
-
- if (dc_plane_state)
- dc_plane_state_release(dc_plane_state);
-
+ dc_state_release(dc_state);
+release_plane_state:
+ dc_plane_state_release(dc_plane_state);
This clean was intended to be reused for now and for future changes, and
the changes here remove the reusability. Also "cleanup" is commonly used
already.
return dc_result;
}
I guess the intention was to reduce goto statements. If that's the case,
it would be better to eliminate all goto and then to remove cleanup +
two checks.
On the other hand, I don't see anything wrong with goto/cleanup approach
either. Multiple exits in a function do not hurt if managed correctly.
