linux.git/drivers/platform/loongarch, branch master Linux kernel source tree platform/loongarch: laptop: Explicitly reset bl_powered state when suspend 2026-07-24T08:33:14+00:00 Zixing Liu liushuyu@aosc.io 2026-07-24T08:33:14+00:00 91a70492c03040d51b36f595530d6491d5d6c541 On EAECIS NL60R with EC firmware version 1.11, resuming from S3 has a very high chance (>90%) of causing the EC to lose the previous backlight power state. When this happens, the laptop resumes normally from S3, but the backlight remains off (when shining on the screen with a flash light, we can see the screen contents are updating normally). Since there is no generic way to query the EC's backlight state on Loongson laptop platforms, assume the worst-case scenario and restart the backlight power inside the kernel each time the system resumes. Cc: stable@vger.kernel.org Fixes: 53c762b47f72 ("platform/loongarch: laptop: Add backlight power control support") Tested-by: Yao Zi <me@ziyao.cc> Tested-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Zixing Liu <liushuyu@aosc.io> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
On EAECIS NL60R with EC firmware version 1.11, resuming from S3 has a
very high chance (>90%) of causing the EC to lose the previous backlight
power state. When this happens, the laptop resumes normally from S3, but
the backlight remains off (when shining on the screen with a flash light,
we can see the screen contents are updating normally).

Since there is no generic way to query the EC's backlight state on
Loongson laptop platforms, assume the worst-case scenario and restart
the backlight power inside the kernel each time the system resumes.

Cc: stable@vger.kernel.org
Fixes: 53c762b47f72 ("platform/loongarch: laptop: Add backlight power control support")
Tested-by: Yao Zi <me@ziyao.cc>
Tested-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Zixing Liu <liushuyu@aosc.io>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
platform/loongarch: laptop: Stop setting acpi_device_class() 2026-07-24T08:33:14+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2026-07-24T08:33:14+00:00 cf4dd800e49d35d48ebd63d511a6e200f39176f7 The driver populates acpi_device_class() which is never read afterward, so make it stop doing that and drop the symbol defined specifically for this purpose. No intentional functional impact. This change will facilitate the removal of "device_class" from "struct acpi_device_pnp" in the future. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
The driver populates acpi_device_class() which is never read afterward,
so make it stop doing that and drop the symbol defined specifically for
this purpose.

No intentional functional impact.

This change will facilitate the removal of "device_class" from "struct
acpi_device_pnp" in the future.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
platform/loongarch: laptop: Unregister generic_sub_drivers on exit 2025-06-07T03:37:15+00:00 Yao Zi ziyao@disroot.org 2025-06-05T12:34:46+00:00 f78fb2576f22b0ba5297412a9aa7691920666c41 Without correct unregisteration, ACPI notify handlers and the platform drivers installed by generic_subdriver_init() will become dangling references after removing the loongson_laptop module, triggering various kernel faults when a hotkey is sent or at kernel shutdown. Cc: stable@vger.kernel.org Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver") Signed-off-by: Yao Zi <ziyao@disroot.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
Without correct unregisteration, ACPI notify handlers and the platform
drivers installed by generic_subdriver_init() will become dangling
references after removing the loongson_laptop module, triggering various
kernel faults when a hotkey is sent or at kernel shutdown.

Cc: stable@vger.kernel.org
Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
platform/loongarch: laptop: Add backlight power control support 2025-06-07T03:37:15+00:00 Yao Zi ziyao@disroot.org 2025-06-05T12:34:46+00:00 53c762b47f726e4079a1f06f684bce2fc0d56fba loongson_laptop_turn_{on,off}_backlight() are designed for controlling the power of the backlight, but they aren't really used in the driver previously. Unify these two functions since they only differ in arguments passed to ACPI method, and wire up loongson_laptop_backlight_update() to update the power state of the backlight as well. Tested on the TongFang L860-T2 Loongson-3A5000 laptop. Cc: stable@vger.kernel.org Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver") Signed-off-by: Yao Zi <ziyao@disroot.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
loongson_laptop_turn_{on,off}_backlight() are designed for controlling
the power of the backlight, but they aren't really used in the driver
previously.

Unify these two functions since they only differ in arguments passed to
ACPI method, and wire up loongson_laptop_backlight_update() to update
the power state of the backlight as well. Tested on the TongFang L860-T2
Loongson-3A5000 laptop.

Cc: stable@vger.kernel.org
Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
platform/loongarch: laptop: Get brightness setting from EC on probe 2025-06-06T10:51:16+00:00 Yao Zi ziyao@disroot.org 2025-06-05T12:34:46+00:00 1205088fd0393bd9eae96b62bf1e4b9eb1b73edf Previously during driver probe, 1 is unconditionally taken as current brightness value and set to props.brightness, which will be considered as the brightness before suspend and restored to EC on resume. Since a brightness value of 1 almost never matches EC's state on coldboot (my laptop's EC defaults to 80), this causes surprising changes of screen brightness on the first time of resume after coldboot. Let's get brightness from EC and take it as the current brightness on probe of the laptop driver to avoid the surprising behavior. Tested on TongFang L860-T2 Loongson-3A5000 laptop. Cc: stable@vger.kernel.org Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver") Signed-off-by: Yao Zi <ziyao@disroot.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
Previously during driver probe, 1 is unconditionally taken as current
brightness value and set to props.brightness, which will be considered
as the brightness before suspend and restored to EC on resume. Since a
brightness value of 1 almost never matches EC's state on coldboot (my
laptop's EC defaults to 80), this causes surprising changes of screen
brightness on the first time of resume after coldboot.

Let's get brightness from EC and take it as the current brightness on
probe of the laptop driver to avoid the surprising behavior. Tested on
TongFang L860-T2 Loongson-3A5000 laptop.

Cc: stable@vger.kernel.org
Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
ACPI: EC: Enable EC support on LoongArch by default 2024-12-18T19:23:59+00:00 Huacai Chen chenhuacai@loongson.cn 2024-12-17T07:37:04+00:00 0674188f2f4d38d74aa863f17373d76256f2ed09 Commit a6021aa24f6417416d933 ("ACPI: EC: make EC support compile-time conditional") only enable ACPI_EC on X86 by default, but the embedded controller is also widely used on LoongArch laptops so we also enable ACPI_EC for LoongArch. The laptop driver cannot work without EC, so also update the dependency of LOONGSON_LAPTOP to let it depend on APCI_EC. Fixes: a6021aa24f6417416d933 ("ACPI: EC: make EC support compile-time conditional") Reported-by: Xiaotian Wu <wuxiaotian@loongson.cn> Tested-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Link: https://patch.msgid.link/20241217073704.3339587-1-chenhuacai@loongson.cn [ rjw: Added Fixes: ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Commit a6021aa24f6417416d933 ("ACPI: EC: make EC support compile-time
conditional") only enable ACPI_EC on X86 by default, but the embedded
controller is also widely used on LoongArch laptops so we also enable
ACPI_EC for LoongArch.

The laptop driver cannot work without EC, so also update the dependency
of LOONGSON_LAPTOP to let it depend on APCI_EC.

Fixes: a6021aa24f6417416d933 ("ACPI: EC: make EC support compile-time conditional")
Reported-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Tested-by: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/20241217073704.3339587-1-chenhuacai@loongson.cn
[ rjw: Added Fixes: ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
platform/loongarch: laptop: Fix possible UAF and simplify generic_acpi_laptop_init() 2022-10-29T08:29:31+00:00 Yang Yingliang yangyingliang@huawei.com 2022-10-29T08:29:31+00:00 d81916910f7498fe7a768697e0101d488f9fe665 Currently the return value of 'sub_driver->init' is not checked. If sparse_keymap_setup() called in the init function fails, 'generic_ inputdev' is freed, then it will lead a UAF when using it in generic_ acpi_laptop_init(). Fix it by checking the return value and setting generic_inputdev to NULL after free, so as to avoid double free it. The error code in generic_subdriver_init() is always negative, so the return of generic_subdriver_init() can be simplified. Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
Currently the return value of 'sub_driver->init' is not checked. If
sparse_keymap_setup() called in the init function fails, 'generic_
inputdev' is freed, then it will lead a UAF when using it in generic_
acpi_laptop_init(). Fix it by checking the return value and setting
generic_inputdev to NULL after free, so as to avoid double free it.

The error code in generic_subdriver_init() is always negative, so the
return of generic_subdriver_init() can be simplified.

Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
platform/loongarch: laptop: Adjust resume order for loongson_hotkey_resume() 2022-10-29T08:29:31+00:00 Huacai Chen chenhuacai@loongson.cn 2022-10-29T08:29:31+00:00 fbe605ab157b174385b3f19ce33928d3548a9b09 Some laptops don't support SW_LID, but still have backlight control, move backlight resuming before SW_LID event handling so as to avoid backlight mistake due to early return. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
Some laptops don't support SW_LID, but still have backlight control,
move backlight resuming before SW_LID event handling so as to avoid
backlight mistake due to early return.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
LoongArch: Add ACPI-based generic laptop driver 2022-10-12T08:36:20+00:00 Jianmin Lv lvjianmin@loongson.cn 2022-10-12T08:36:20+00:00 6246ed09111fbb17168619006b4380103c6673c3 This add ACPI-based generic laptop driver for Loongson-3. Some of the codes are derived from drivers/platform/x86/thinkpad_acpi.c. Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 
This add ACPI-based generic laptop driver for Loongson-3. Some of the
codes are derived from drivers/platform/x86/thinkpad_acpi.c.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>