diff options
author | Zhang Rui <rui.zhang@intel.com> | 2009-04-09 02:24:35 -0400 |
---|---|---|
committer | Len Brown <len.brown@intel.com> | 2009-04-11 01:05:58 -0400 |
commit | e047cca66c6bb0b1c346e91305011aab79dfc4b0 (patch) | |
tree | c656787366e002db0ce091a1629f19d0566f94fa /drivers/acpi/video.c | |
parent | d848223808c5d21e1b3cea090047e34722c6254b (diff) |
ACPI video: handle indexed _BQC correctly
In the current code, for a box with an indexed _BQC method, we
1. get the current brightness level by evaluating _BQC
2. set the value gotten in step 1 to _BCM
3. get the current brightness level again
4. set the _BQC_use_index flag if the results gotten
in step 1 and in step 3 don't equal.
But this logic doesn't work actually, because the _BQC_use_index
is not set when acpi_video_device_lcd_set_level is invoked.
This results in a failure in step 2.
http://bugzilla.kernel.org/show_bug.cgi?id=12249#c83
Now, we set the _BQC_use_index flag after invoking _BQC for the first
time. And reevaluate the _BQC to get the correct brightness level.
Signed-off-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 | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index cd4fb7543a90..346277f93cda 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c | |||
@@ -807,12 +807,19 @@ acpi_video_init_brightness(struct acpi_video_device *device) | |||
807 | br->flags._BCM_use_index = br->flags._BCL_use_index; | 807 | br->flags._BCM_use_index = br->flags._BCL_use_index; |
808 | 808 | ||
809 | /* _BQC uses INDEX while _BCL uses VALUE in some laptops */ | 809 | /* _BQC uses INDEX while _BCL uses VALUE in some laptops */ |
810 | br->curr = max_level; | 810 | br->curr = level_old = max_level; |
811 | |||
812 | if (!device->cap._BQC) | ||
813 | goto set_level; | ||
814 | |||
811 | result = acpi_video_device_lcd_get_level_current(device, &level_old); | 815 | result = acpi_video_device_lcd_get_level_current(device, &level_old); |
812 | if (result) | 816 | if (result) |
813 | goto out_free_levels; | 817 | goto out_free_levels; |
814 | 818 | ||
815 | result = acpi_video_device_lcd_set_level(device, br->curr); | 819 | /* |
820 | * Set the level to maximum and check if _BQC uses indexed value | ||
821 | */ | ||
822 | result = acpi_video_device_lcd_set_level(device, max_level); | ||
816 | if (result) | 823 | if (result) |
817 | goto out_free_levels; | 824 | goto out_free_levels; |
818 | 825 | ||
@@ -820,25 +827,19 @@ acpi_video_init_brightness(struct acpi_video_device *device) | |||
820 | if (result) | 827 | if (result) |
821 | goto out_free_levels; | 828 | goto out_free_levels; |
822 | 829 | ||
823 | if ((level != level_old) && !br->flags._BCM_use_index) { | 830 | br->flags._BQC_use_index = (level == max_level ? 0 : 1); |
824 | /* Note: | 831 | |
825 | * This piece of code does not work correctly if the current | 832 | if (!br->flags._BQC_use_index) |
826 | * brightness levels is 0. | 833 | goto set_level; |
827 | * But I guess boxes that boot with such a dark screen are rare | 834 | |
828 | * and no more code is needed to cover this specifial case. | 835 | if (br->flags._BCL_reversed) |
829 | */ | 836 | level_old = (br->count - 1) - level_old; |
830 | 837 | level_old = br->levels[level_old]; | |
831 | if (level_ac_battery != 2) { | 838 | |
832 | /* | 839 | set_level: |
833 | * For now, we don't support the _BCL like this: | 840 | result = acpi_video_device_lcd_set_level(device, level_old); |
834 | * 16, 15, 0, 1, 2, 3, ..., 14, 15, 16 | 841 | if (result) |
835 | * because we may mess up the index returned by _BQC. | 842 | goto out_free_levels; |
836 | * Plus: we have not got a box like this. | ||
837 | */ | ||
838 | ACPI_ERROR((AE_INFO, "_BCL not supported\n")); | ||
839 | } | ||
840 | br->flags._BQC_use_index = 1; | ||
841 | } | ||
842 | 843 | ||
843 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | 844 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
844 | "found %d brightness levels\n", count - 2)); | 845 | "found %d brightness levels\n", count - 2)); |