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>
This commit is contained in:
Zhang Rui 2009-03-18 16:27:14 +08:00 committed by Len Brown
parent d32f69470c
commit d80fb99fdc

View File

@ -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;