On Friday, July 12, 2019 12:00:33 PM CEST Hans de Goede wrote: > Some machines change the brightness themselves when a brightness hotkey > gets pressed, despite us telling them not to. This causes the brightness to > go two steps up / down when the hotkey is pressed. This is esp. a problem > on older machines with only a few brightness levels. > > This commit adds a new hw_changes_brightness quirk which makes > acpi_video_device_notify() only call backlight_force_update(..., > BACKLIGHT_UPDATE_HOTKEY) and not do anything else, notifying userspace that > the brightness was changed and leaving it at that fixing the dual step > problem. > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204077 > Cc: Kacper Piwiński <cosiekvfj@xxxxx> > Reported-and-tested-by: Kacper Piwiński <cosiekvfj@xxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/acpi/acpi_video.c | 37 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c > index 9489ffc06411..4f325e47519f 100644 > --- a/drivers/acpi/acpi_video.c > +++ b/drivers/acpi/acpi_video.c > @@ -60,6 +60,12 @@ module_param(report_key_events, int, 0644); > MODULE_PARM_DESC(report_key_events, > "0: none, 1: output changes, 2: brightness changes, 3: all"); > > +static int hw_changes_brightness = -1; > +module_param(hw_changes_brightness, int, 0644); > +MODULE_PARM_DESC(hw_changes_brightness, > + "Set this to 1 on buggy hw which changes the brightness itself when " > + "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness"); > + > /* > * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be > * assumed even if not actually set. > @@ -405,6 +411,14 @@ static int video_set_report_key_events(const struct dmi_system_id *id) > return 0; > } > > +static int video_hw_changes_brightness( > + const struct dmi_system_id *d) > +{ > + if (hw_changes_brightness == -1) > + hw_changes_brightness = 1; > + return 0; > +} > + > static const struct dmi_system_id video_dmi_table[] = { > /* > * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121 > @@ -529,6 +543,21 @@ static const struct dmi_system_id video_dmi_table[] = { > DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"), > }, > }, > + /* > + * Some machines change the brightness themselves when a brightness > + * hotkey gets pressed, despite us telling them not to. In this case > + * acpi_video_device_notify() should only call backlight_force_update( > + * BACKLIGHT_UPDATE_HOTKEY) and not do anything else. > + */ > + { > + /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */ > + .callback = video_hw_changes_brightness, > + .ident = "Packard Bell EasyNote MZ35", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"), > + DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"), > + }, > + }, > {} > }; > > @@ -1612,6 +1641,14 @@ static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data) > bus = video_device->video; > input = bus->input; > > + if (hw_changes_brightness > 0) { > + if (video_device->backlight) > + backlight_force_update(video_device->backlight, > + BACKLIGHT_UPDATE_HOTKEY); > + acpi_notifier_call_chain(device, event, 0); > + return; > + } > + > switch (event) { > case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */ > brightness_switch_event(video_device, event); > Applied, thanks!
