diff options
| author | Matthew Garrett <mjg59@srcf.ucam.org> | 2007-12-26 03:03:26 +0100 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-02-02 04:43:31 +0100 |
| commit | 38531e6fe51ad5c7dfe72e0e066b5f54bc1921cd (patch) | |
| tree | 84d20e98033a647569b751aa43419d166f587c6d /drivers/acpi/video.c | |
| parent | x86: fix bootup crash in native_read_tsc() (diff) | |
| download | linux-38531e6fe51ad5c7dfe72e0e066b5f54bc1921cd.tar.xz linux-38531e6fe51ad5c7dfe72e0e066b5f54bc1921cd.zip | |
ACPI: video: Rationalise ACPI backlight implementation
The sysfs backlight class provides no mechanism for querying the
acceptable brightness for a backlight. The ACPI spec states that values
are only valid if they are reported as available by the firmware. Since
we can't provide that information to userspace, instead collapse the
range to the number of actual values that can be set.
http://bugzilla.kernel.org/show_bug.cgi?id=9277
Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index bd77e81e81c1..59639c9c6666 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -292,18 +292,26 @@ static int acpi_video_device_set_state(struct acpi_video_device *device, int sta static int acpi_video_get_brightness(struct backlight_device *bd) { unsigned long cur_level; + int i; struct acpi_video_device *vd = (struct acpi_video_device *)bl_get_data(bd); acpi_video_device_lcd_get_level_current(vd, &cur_level); - return (int) cur_level; + for (i = 2; i < vd->brightness->count; i++) { + if (vd->brightness->levels[i] == cur_level) + /* The first two entries are special - see page 575 + of the ACPI spec 3.0 */ + return i-2; + } + return 0; } static int acpi_video_set_brightness(struct backlight_device *bd) { - int request_level = bd->props.brightness; + int request_level = bd->props.brightness+2; struct acpi_video_device *vd = (struct acpi_video_device *)bl_get_data(bd); - acpi_video_device_lcd_set_level(vd, request_level); + acpi_video_device_lcd_set_level(vd, + vd->brightness->levels[request_level]); return 0; } @@ -652,7 +660,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) kfree(obj); if (device->cap._BCL && device->cap._BCM && device->cap._BQC && max_level > 0){ - unsigned long tmp; static int count = 0; char *name; name = kzalloc(MAX_NAME_LEN, GFP_KERNEL); @@ -660,11 +667,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) return; sprintf(name, "acpi_video%d", count++); - acpi_video_device_lcd_get_level_current(device, &tmp); device->backlight = backlight_device_register(name, NULL, device, &acpi_backlight_ops); - device->backlight->props.max_brightness = max_level; - device->backlight->props.brightness = (int)tmp; + device->backlight->props.max_brightness = device->brightness->count-3; + device->backlight->props.brightness = acpi_video_get_brightness(device->backlight); backlight_update_status(device->backlight); kfree(name); |