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, 170 insertions, 0 deletions

diff --git a/Documentation/gpu/amdgpu/thermal.rst b/Documentation/gpu/amdgpu/thermal.rst
new file mode 100644
index 000000000..1768a106a
--- /dev/null
+++ b/Documentation/gpu/amdgpu/thermal.rst
@@ -0,0 +1,170 @@
+===========================================
+ GPU Power/Thermal Controls and Monitoring
+===========================================
+
+HWMON Interfaces
+================
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: hwmon
+
+GPU sysfs Power State Interfaces
+================================
+
+GPU power controls are exposed via sysfs files.
+
+power_dpm_state
+---------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: power_dpm_state
+
+power_dpm_force_performance_level
+---------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: power_dpm_force_performance_level
+
+pp_table
+--------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: pp_table
+
+pp_od_clk_voltage
+-----------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: pp_od_clk_voltage
+
+pp_dpm_*
+--------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie
+
+pp_power_profile_mode
+---------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: pp_power_profile_mode
+
+pm_policy
+---------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: pm_policy
+
+\*_busy_percent
+---------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: gpu_busy_percent
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: mem_busy_percent
+
+gpu_metrics
+-----------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: gpu_metrics
+
+fan_curve
+---------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: fan_curve
+
+acoustic_limit_rpm_threshold
+----------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: acoustic_limit_rpm_threshold
+
+acoustic_target_rpm_threshold
+-----------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: acoustic_target_rpm_threshold
+
+fan_target_temperature
+----------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: fan_target_temperature
+
+fan_minimum_pwm
+---------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: fan_minimum_pwm
+
+fan_zero_rpm_enable
+----------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: fan_zero_rpm_enable
+
+fan_zero_rpm_stop_temperature
+-----------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: fan_zero_rpm_stop_temperature
+
+GFXOFF
+======
+
+GFXOFF is a feature found in most recent GPUs that saves power at runtime. The
+card's RLC (RunList Controller) firmware powers off the gfx engine
+dynamically when there is no workload on gfx or compute pipes. GFXOFF is on by
+default on supported GPUs.
+
+Userspace can interact with GFXOFF through a debugfs interface (all values in
+`uint32_t`, unless otherwise noted):
+
+``amdgpu_gfxoff``
+-----------------
+
+Use it to enable/disable GFXOFF, and to check if it's current enabled/disabled::
+
+  $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff
+  01
+
+- Write 0 to disable it, and 1 to enable it.
+- Read 0 means it's disabled, 1 it's enabled.
+
+If it's enabled, that means that the GPU is free to enter into GFXOFF mode as
+needed. Disabled means that it will never enter GFXOFF mode.
+
+``amdgpu_gfxoff_status``
+------------------------
+
+Read it to check current GFXOFF's status of a GPU::
+
+  $ xxd -l1 -p /sys/kernel/debug/dri/0/amdgpu_gfxoff_status
+  02
+
+- 0: GPU is in GFXOFF state, the gfx engine is powered down.
+- 1: Transition out of GFXOFF state
+- 2: Not in GFXOFF state
+- 3: Transition into GFXOFF state
+
+If GFXOFF is enabled, the value will be transitioning around [0, 3], always
+getting into 0 when possible. When it's disabled, it's always at 2. Returns
+``-EINVAL`` if it's not supported.
+
+``amdgpu_gfxoff_count``
+-----------------------
+
+Read it to get the total GFXOFF entry count at the time of query since system
+power-up. The value is an `uint64_t` type, however, due to firmware limitations,
+it can currently overflow as an `uint32_t`. *Only supported in vangogh*
+
+``amdgpu_gfxoff_residency``
+---------------------------
+
+Write 1 to amdgpu_gfxoff_residency to start logging, and 0 to stop. Read it to
+get average GFXOFF residency % multiplied by 100 during the last logging
+interval. E.g. a value of 7854 means 78.54% of the time in the last logging
+interval the GPU was in GFXOFF mode. *Only supported in vangogh*