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, 65 insertions, 0 deletions

diff --git a/Documentation/kbuild/bash-completion.rst b/Documentation/kbuild/bash-completion.rst
new file mode 100644
index 000000000..2b52dbcd0
--- /dev/null
+++ b/Documentation/kbuild/bash-completion.rst
@@ -0,0 +1,65 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+==========================
+Bash completion for Kbuild
+==========================
+
+The kernel build system is written using Makefiles, and Bash completion
+for the `make` command is available through the `bash-completion`_ project.
+
+However, the Makefiles for the kernel build are complex. The generic completion
+rules for the `make` command do not provide meaningful suggestions for the
+kernel build system, except for the options of the `make` command itself.
+
+To enhance completion for various variables and targets, the kernel source
+includes its own completion script at `scripts/bash-completion/make`.
+
+This script provides additional completions when working within the kernel tree.
+Outside the kernel tree, it defaults to the generic completion rules for the
+`make` command.
+
+Prerequisites
+=============
+
+The script relies on helper functions provided by `bash-completion`_ project.
+Please ensure it is installed on your system. On most distributions, you can
+install the `bash-completion` package through the standard package manager.
+
+How to use
+==========
+
+You can source the script directly::
+
+  $ source scripts/bash-completion/make
+
+Or, you can copy it into the search path for Bash completion scripts.
+For example::
+
+  $ mkdir -p ~/.local/share/bash-completion/completions
+  $ cp scripts/bash-completion/make ~/.local/share/bash-completion/completions/
+
+Details
+=======
+
+The additional completion for Kbuild is enabled in the following cases:
+
+ - You are in the root directory of the kernel source.
+ - You are in the top-level build directory created by the O= option
+   (checked via the `source` symlink pointing to the kernel source).
+ - The -C make option specifies the kernel source or build directory.
+ - The -f make option specifies a file in the kernel source or build directory.
+
+If none of the above are met, it falls back to the generic completion rules.
+
+The completion supports:
+
+  - Commonly used targets, such as `all`, `menuconfig`, `dtbs`, etc.
+  - Make (or environment) variables, such as `ARCH`, `LLVM`, etc.
+  - Single-target builds (`foo/bar/baz.o`)
+  - Configuration files (`*_defconfig` and `*.config`)
+
+Some variables offer intelligent behavior. For instance, `CROSS_COMPILE=`
+followed by a TAB displays installed toolchains. The list of defconfig files
+shown depends on the value of the `ARCH=` variable.
+
+.. _bash-completion: https://github.com/scop/bash-completion/