Subject: support reversed _BCL method in ACPI video driver From: Zhang Rui <rui.zhang@xxxxxxxxx> 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@xxxxxxxxx> Acked-by: Matthew Garrett <mjg59@xxxxxxxxxxxxx> Acked-by: Thomas Renninger <trenn@xxxxxxx> --- drivers/acpi/video.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) Index: linux-2.6/drivers/acpi/video.c =================================================================== --- linux-2.6.orig/drivers/acpi/video.c 2009-03-17 14:52:09.000000000 +0800 +++ linux-2.6/drivers/acpi/video.c 2009-03-17 14:53:04.000000000 +0800 @@ -170,6 +170,7 @@ 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 @@ } 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; -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
