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, 43 insertions, 0 deletions

diff --git a/Documentation/hwmon/userspace-tools.rst b/Documentation/hwmon/userspace-tools.rst
new file mode 100644
index 000000000..bf3797c8e
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+++ b/Documentation/hwmon/userspace-tools.rst
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+Userspace tools
+===============
+
+Introduction
+------------
+
+Most mainboards have sensor chips to monitor system health (like temperatures,
+voltages, fans speed). They are often connected through an I2C bus, but some
+are also connected directly through the ISA bus.
+
+The kernel drivers make the data from the sensor chips available in the /sys
+virtual filesystem. Userspace tools are then used to display the measured
+values or configure the chips in a more friendly manner.
+
+Lm-sensors
+----------
+
+Core set of utilities that will allow you to obtain health information,
+setup monitoring limits etc. You can get them on their homepage
+http://www.lm-sensors.org/ or as a package from your Linux distribution.
+
+If from website:
+Get lm-sensors from project web site. Please note, you need only userspace
+part, so compile with "make user" and install with "make user_install".
+
+General hints to get things working:
+
+0) get lm-sensors userspace utils
+1) compile all drivers in I2C and Hardware Monitoring sections as modules
+   in your kernel
+2) run sensors-detect script, it will tell you what modules you need to load.
+3) load them and run "sensors" command, you should see some results.
+4) fix sensors.conf, labels, limits, fan divisors
+5) if any more problems consult FAQ, or documentation
+
+Other utilities
+---------------
+
+If you want some graphical indicators of system health look for applications
+like: gkrellm, ksensors, xsensors, wmtemp, wmsensors, wmgtemp, ksysguardd,
+hardware-monitor
+
+If you are server administrator you can try snmpd or mrtgutils.