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authorZhang Rui <rui.zhang@intel.com>2009-03-18 16:27:14 +0800
committerLen Brown <len.brown@intel.com>2009-03-27 21:56:24 -0400
commitd80fb99fdcd56f4934f11cc44ca016463842dc8b (patch)
treeecc0e6c7beab6b77190353873026716685c41029 /drivers/acpi/video.c
parentd32f69470c2081ffdfd82740ac19f940790f9e93 (diff)
ACPI video: support reversed _BCL method in ACPI video driver
The brightness levels returned by _BCL package are in a reversed order on some laptops. http://bugzilla.kernel.org/show_bug.cgi?id=12037 http://bugzilla.kernel.org/show_bug.cgi?id=12302 http://bugzilla.kernel.org/show_bug.cgi?id=12235 sort the _BCL packge in case it's reversed. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Matthew Garrett <mjg59@srcf.ucam.org> Acked-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/video.c')
-rw-r--r--drivers/acpi/video.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 398b3eee37f..dc84970ce1e 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -170,6 +170,7 @@ struct acpi_video_device_cap {
struct acpi_video_brightness_flags {
u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
+ u8 _BCL_reversed:1; /* _BCL package is in a reversed order*/
};
struct acpi_video_device_brightness {
@@ -744,9 +745,14 @@ acpi_video_init_brightness(struct acpi_video_device *device)
} else if (level_ac_battery > 2)
ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package\n"));
- /* sort all the supported brightness levels */
- sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
- acpi_video_cmp_level, NULL);
+ /* Check if the _BCL package is in a reversed order */
+ if (max_level == br->levels[2]) {
+ br->flags._BCL_reversed = 1;
+ sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
+ acpi_video_cmp_level, NULL);
+ } else if (max_level != br->levels[count - 1])
+ ACPI_ERROR((AE_INFO,
+ "Found unordered _BCL package\n"));
br->count = count;
device->brightness = br;