From 26cbe119f99c86dcb4a0136d2bc73c0c716d80e4 Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Wed, 13 May 2026 01:21:41 +0200 Subject: [PATCH] platform/x86: uniwill-laptop: Do not enable the charging limit even when forced MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It seems that on some older models (~2020) the battery charging limit can permanently damage the battery. Prevent users from enabling this feature thru the "force" module parameter to avoid causing permanent hardware damage on such devices. Fixes: d050479693bb ("platform/x86: Add Uniwill laptop driver") Link: https://www.reddit.com/r/XMG_gg/comments/ld9yyf/battery_limit_hidden_function_discovered_on/ Reviewed-by: Werner Sembach Reviewed-by: Ilpo Järvinen Signed-off-by: Armin Wolf Link: https://patch.msgid.link/20260512232145.329260-5-W_Armin@gmx.de Signed-off-by: Ilpo Järvinen --- Documentation/admin-guide/laptops/uniwill-laptop.rst | 10 ++++++++++ drivers/platform/x86/uniwill/uniwill-acpi.c | 4 ++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/laptops/uniwill-laptop.rst b/Documentation/admin-guide/laptops/uniwill-laptop.rst index 561334865feb..1f3ca84c7d88 100644 --- a/Documentation/admin-guide/laptops/uniwill-laptop.rst +++ b/Documentation/admin-guide/laptops/uniwill-laptop.rst @@ -43,6 +43,11 @@ Support for changing the platform performance mode is currently not implemented. Battery Charging Control ------------------------ +.. warning:: Some devices do not properly implement the charging threshold interface. Forcing + the driver to enable access to said interface on such devices might damage the + battery [1]_. Because of this the driver will not enable said feature even when + using the ``force`` module parameter. + The ``uniwill-laptop`` driver supports controlling the battery charge limit. This happens over the standard ``charge_control_end_threshold`` power supply sysfs attribute. All values between 1 and 100 percent are supported. @@ -70,3 +75,8 @@ The ``uniwill-laptop`` driver allows to set the configurable TGP for devices wit allow it. See Documentation/ABI/testing/sysfs-driver-uniwill-laptop for details. + +References +========== + +.. [1] https://www.reddit.com/r/XMG_gg/comments/ld9yyf/battery_limit_hidden_function_discovered_on/ diff --git a/drivers/platform/x86/uniwill/uniwill-acpi.c b/drivers/platform/x86/uniwill/uniwill-acpi.c index 481c4cf46e63..8cc01bec77b9 100644 --- a/drivers/platform/x86/uniwill/uniwill-acpi.c +++ b/drivers/platform/x86/uniwill/uniwill-acpi.c @@ -2507,8 +2507,8 @@ static int __init uniwill_init(void) } if (force) { - /* Assume that the device supports all features */ - device_descriptor.features = UINT_MAX; + /* Assume that the device supports all features except the charge limit */ + device_descriptor.features = UINT_MAX & ~UNIWILL_FEATURE_BATTERY; pr_warn("Enabling potentially unsupported features\n"); }