drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 108 insertions, 0 deletions

diff --git a/Documentation/gpu/vc4.rst b/Documentation/gpu/vc4.rst
new file mode 100644
index 000000000..5e5e92e40
--- /dev/null
+++ b/Documentation/gpu/vc4.rst
@@ -0,0 +1,108 @@
+=====================================
+ drm/vc4 Broadcom VC4 Graphics Driver
+=====================================
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_drv.c
+   :doc: Broadcom VC4 Graphics Driver
+
+Display Hardware Handling
+=========================
+
+This section covers everything related to the display hardware including
+the mode setting infrastructure, plane, sprite and cursor handling and
+display, output probing and related topics.
+
+Pixel Valve (DRM CRTC)
+----------------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_crtc.c
+   :doc: VC4 CRTC module
+
+HVS
+---
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_hvs.c
+   :doc: VC4 HVS module.
+
+HVS planes
+----------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_plane.c
+   :doc: VC4 plane module
+
+HDMI encoder
+------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_hdmi.c
+   :doc: VC4 Falcon HDMI module
+
+DSI encoder
+-----------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_dsi.c
+   :doc: VC4 DSI0/DSI1 module
+
+DPI encoder
+-----------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_dpi.c
+   :doc: VC4 DPI module
+
+VEC (Composite TV out) encoder
+------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_vec.c
+   :doc: VC4 SDTV module
+
+KUnit Tests
+===========
+
+The VC4 Driver uses KUnit to perform driver-specific unit and
+integration tests.
+
+These tests are using a mock driver and can be ran using the
+command below, on either arm or arm64 architectures,
+
+.. code-block:: bash
+
+	$ ./tools/testing/kunit/kunit.py run \
+		--kunitconfig=drivers/gpu/drm/vc4/tests/.kunitconfig \
+		--cross_compile aarch64-linux-gnu- --arch arm64
+
+Parts of the driver that are currently covered by tests are:
+ * The HVS to PixelValve dynamic FIFO assignment, for the BCM2835-7
+   and BCM2711.
+
+Memory Management and 3D Command Submission
+===========================================
+
+This section covers the GEM implementation in the vc4 driver.
+
+GPU buffer object (BO) management
+---------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_bo.c
+   :doc: VC4 GEM BO management support
+
+V3D binner command list (BCL) validation
+----------------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_validate.c
+   :doc: Command list validator for VC4.
+
+V3D render command list (RCL) generation
+----------------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_render_cl.c
+   :doc: Render command list generation
+
+Shader validator for VC4
+---------------------------
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_validate_shaders.c
+   :doc: Shader validator for VC4.
+
+V3D Interrupts
+--------------
+
+.. kernel-doc:: drivers/gpu/drm/vc4/vc4_irq.c
+   :doc: Interrupt management for the V3D engine