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authorLinus Torvalds <torvalds@linux-foundation.org>2014-07-18 16:32:51 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-07-21 15:43:56 +0400
commit8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 (patch)
tree8fd45f56ceeb1857f9e0baaf0cb7ac0a926ac2a8 /drivers/acpi
parent9a3c4145af32125c5ee39c0272662b47307a8323 (diff)
downloadlinux-8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7.tar.xz
ACPI / video: Fix backlight taking 2 steps on a brightness up/down keypress
In various scenarious userspace will respond to brightness up/down keypresses by increasing/decreasing the backlight brightness itself. If the kernel then also changes the brightness this results in the brightness having changed 2 steps for a single keypress which is undesirable. See e.g. : https://bugs.launchpad.net/gnome-settings-daemon/+bug/527157 http://askubuntu.com/questions/173921/why-does-my-thinkpad-brightness-control-skip-steps This commit delays responding to brightness up/down keypresses by 100 ms and if userspace in that time responds by changing the backlight itself, cancels the kernels own handling of these keypresses, fixing the 2 steps issue. Link: http://marc.info/?l=linux-kernel&m=140535721100839&w=2 [hdegoede@redhat.com: Move the delayed_work struct into struct acpi_video_device instead of having it as a global] [hdegoede@redhat.com: Keep brightness_switch_enabled as a boolean and always delay the keypress handling] Tested-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/video.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 350d52a8f781..bfe1fa2fb5d1 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -204,6 +204,8 @@ struct acpi_video_device {
struct acpi_video_device_flags flags;
struct acpi_video_device_cap cap;
struct list_head entry;
+ struct delayed_work switch_brightness_work;
+ int switch_brightness_event;
struct acpi_video_bus *video;
struct acpi_device *dev;
struct acpi_video_device_brightness *brightness;
@@ -230,8 +232,7 @@ static int acpi_video_device_lcd_get_level_current(
unsigned long long *level, bool raw);
static int acpi_video_get_next_level(struct acpi_video_device *device,
u32 level_current, u32 event);
-static int acpi_video_switch_brightness(struct acpi_video_device *device,
- int event);
+static void acpi_video_switch_brightness(struct work_struct *work);
static bool acpi_video_use_native_backlight(void)
{
@@ -275,6 +276,7 @@ static int acpi_video_set_brightness(struct backlight_device *bd)
int request_level = bd->props.brightness + 2;
struct acpi_video_device *vd = bl_get_data(bd);
+ cancel_delayed_work(&vd->switch_brightness_work);
return acpi_video_device_lcd_set_level(vd,
vd->brightness->levels[request_level]);
}
@@ -1188,6 +1190,8 @@ acpi_video_bus_get_one_device(struct acpi_device *device,
data->device_id = device_id;
data->video = video;
data->dev = device;
+ INIT_DELAYED_WORK(&data->switch_brightness_work,
+ acpi_video_switch_brightness);
attribute = acpi_video_get_device_attr(video, device_id);
@@ -1410,15 +1414,18 @@ acpi_video_get_next_level(struct acpi_video_device *device,
}
}
-static int
-acpi_video_switch_brightness(struct acpi_video_device *device, int event)
+static void
+acpi_video_switch_brightness(struct work_struct *work)
{
+ struct acpi_video_device *device = container_of(to_delayed_work(work),
+ struct acpi_video_device, switch_brightness_work);
unsigned long long level_current, level_next;
+ int event = device->switch_brightness_event;
int result = -EINVAL;
/* no warning message if acpi_backlight=vendor or a quirk is used */
if (!acpi_video_verify_backlight_support())
- return 0;
+ return;
if (!device->brightness)
goto out;
@@ -1440,8 +1447,6 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
out:
if (result)
printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
-
- return result;
}
int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
@@ -1609,6 +1614,16 @@ static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
return;
}
+static void brightness_switch_event(struct acpi_video_device *video_device,
+ u32 event)
+{
+ if (!brightness_switch_enabled)
+ return;
+
+ video_device->switch_brightness_event = event;
+ schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
+}
+
static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
{
struct acpi_video_device *video_device = data;
@@ -1626,28 +1641,23 @@ static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
switch (event) {
case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
- if (brightness_switch_enabled)
- acpi_video_switch_brightness(video_device, event);
+ brightness_switch_event(video_device, event);
keycode = KEY_BRIGHTNESS_CYCLE;
break;
case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
- if (brightness_switch_enabled)
- acpi_video_switch_brightness(video_device, event);
+ brightness_switch_event(video_device, event);
keycode = KEY_BRIGHTNESSUP;
break;
case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
- if (brightness_switch_enabled)
- acpi_video_switch_brightness(video_device, event);
+ brightness_switch_event(video_device, event);
keycode = KEY_BRIGHTNESSDOWN;
break;
case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
- if (brightness_switch_enabled)
- acpi_video_switch_brightness(video_device, event);
+ brightness_switch_event(video_device, event);
keycode = KEY_BRIGHTNESS_ZERO;
break;
case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
- if (brightness_switch_enabled)
- acpi_video_switch_brightness(video_device, event);
+ brightness_switch_event(video_device, event);
keycode = KEY_DISPLAY_OFF;
break;
default: