* For Windows 8 systems: used to decide if video module
* should skip registering backlight interface of its own.
*/
-static int use_native_backlight_param = 1;
+static int use_native_backlight_param = -1;
module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
-static bool use_native_backlight_dmi = false;
+static bool use_native_backlight_dmi = true;
static int register_count;
static struct mutex video_list_lock;
return 0;
}
+static int __init video_disable_native_backlight(const struct dmi_system_id *d)
+{
+ use_native_backlight_dmi = false;
+ return 0;
+}
+
static struct dmi_system_id video_dmi_table[] __initdata = {
/*
* Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8780w"),
},
},
+
+ /*
+ * These models have a working acpi_video backlight control, and using
+ * native backlight causes a regression where backlight does not work
+ * when userspace is not handling brightness key events. Disable
+ * native_backlight on these to fix this:
+ * https://bugzilla.kernel.org/show_bug.cgi?id=81691
+ */
+ {
+ .callback = video_disable_native_backlight,
+ .ident = "ThinkPad T420",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
+ },
+ },
+ {
+ .callback = video_disable_native_backlight,
+ .ident = "ThinkPad T520",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
+ },
+ },
+
+ /* The native backlight controls do not work on some older machines */
+ {
+ /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
+ .callback = video_disable_native_backlight,
+ .ident = "HP ENVY 15 Notebook",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
+ },
+ },
{}
};