devm_drm_bridge_alloc() is the new API to be used for allocating (and
partially initializing) a private driver struct embedding a struct
drm_bridge.
For many drivers having a simple code flow in the probe function, this
commit does a mass conversion automatically with the following semantic
patch. The changes have been reviewed manually for correctness as well as
to find any false positives.
The patch has been applied with the explicit exclusion of bridge/panel.c,
handled by a separate patch.
After applying the semantic patch, manually fixed these issues:
- 4 drivers need ERR_CAST() instead of PTR_ERR() as the function calling
devm_drm_bridge_alloc() returns a pointer
- re-added empty lines and comments that the script had removed but that
should stay
@@
type T;
identifier C;
identifier BR;
expression DEV;
expression FUNCS;
@@
-T *C;
+T *C;
...
(
-C = devm_kzalloc(DEV, ...);
-if (!C)
- return -ENOMEM;
+C = devm_drm_bridge_alloc(DEV, T, BR, FUNCS);
+if (IS_ERR(C))
+ return PTR_ERR(C);
|
-C = devm_kzalloc(DEV, ...);
-if (!C)
- return ERR_PTR(-ENOMEM);
+C = devm_drm_bridge_alloc(DEV, T, BR, FUNCS);
+if (IS_ERR(C))
+ return PTR_ERR(C);
)
...
-C->BR.funcs = FUNCS;
Reviewed-by: Manikandan Muralidharan <manikandan.m@microchip.com> # microchip-lvds.c
Reviewed-by: Douglas Anderson <dianders@chromium.org> # parade-ps8640
Tested-by: Douglas Anderson <dianders@chromium.org> # parade-ps8640
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250509-drm-bridge-convert-to-alloc-api-v3-2-b8bc1f16d7aa@bootlin.com
[Luca: fixed trivial patch conflict in adv7511_drv.c while applying]
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
The drm_bridge structure contains an encoder pointer that is widely used
by bridge drivers. This pattern is largely documented as deprecated in
other KMS entities for atomic drivers.
However, one of the main use of that pointer is done in attach to just
call drm_bridge_attach on the next bridge to add it to the bridge list.
While this dereferences the bridge->encoder pointer, it's effectively
the same encoder the bridge was being attached to.
We can make it more explicit by adding the encoder the bridge is
attached to to the list of attach parameters. This also removes the need
to dereference bridge->encoder in most drivers.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313-bridge-connector-v6-1-511c54a604fb@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Thomas Zimmermann asked to backmerge -rc6 for drm-misc branches,
there's a few same-area-changed conflicts (xe and amdgpu mostly) that
are getting a bit too annoying.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:
drivers/gpu/drm/meson/meson_encoder_cvbs.c:211:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
.mode_valid = meson_encoder_cvbs_mode_valid,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
->mode_valid() in 'struct drm_bridge_funcs' expects a return type of
'enum drm_mode_status', not 'int'. Adjust the return type of
meson_encoder_cvbs_mode_valid() to match the prototype's to resolve the
warning and CFI failure.
Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102155242.1927166-1-nathan@kernel.org
