From: Hans de Goede <hdegoede@xxxxxxxxxx> commit 3a0cf7ab8df3878a7e2f3d29275b785cf4e7afb6 upstream. Some systems have an ACPI video bus but not ACPI video devices with backlight capability. On these devices brightness key-presses are (logically) not reported through the ACPI video bus. Change how acpi_video_handles_brightness_key_presses() determines if brightness key-presses are handled by the ACPI video driver to avoid vendor specific drivers/platform/x86 drivers filtering out their brightness key-presses even though they are the only ones reporting these presses. Fixes: ed83c9171829 ("platform/x86: panasonic-laptop: Resolve hotkey double trigger bug") Reported-and-tested-by: Stefan Seyfried <seife+kernel@xxxxxxxxxxxxxx> Reported-and-tested-by: Kenneth Chan <kenneth.t.chan@xxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220624112340.10130-2-hdegoede@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/acpi_video.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -73,6 +73,7 @@ module_param(device_id_scheme, bool, 044 static int only_lcd = -1; module_param(only_lcd, int, 0444); +static bool has_backlight; static int register_count; static DEFINE_MUTEX(register_count_mutex); static DEFINE_MUTEX(video_list_lock); @@ -1222,6 +1223,9 @@ acpi_video_bus_get_one_device(struct acp acpi_video_device_bind(video, data); acpi_video_device_find_cap(data); + if (data->cap._BCM && data->cap._BCL) + has_backlight = true; + mutex_lock(&video->device_list_lock); list_add_tail(&data->entry, &video->video_device_list); mutex_unlock(&video->device_list_lock); @@ -2251,6 +2255,7 @@ void acpi_video_unregister(void) if (register_count) { acpi_bus_unregister_driver(&acpi_video_bus); register_count = 0; + has_backlight = false; } mutex_unlock(®ister_count_mutex); } @@ -2272,13 +2277,7 @@ void acpi_video_unregister_backlight(voi bool acpi_video_handles_brightness_key_presses(void) { - bool have_video_busses; - - mutex_lock(&video_list_lock); - have_video_busses = !list_empty(&video_bus_head); - mutex_unlock(&video_list_lock); - - return have_video_busses && + return has_backlight && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS); } EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);