Subject: support _BQC/_BCL/_BCM methods that use index values From: Zhang Rui <rui.zhang@xxxxxxxxx> The input/output of _BQC/_BCL/_BCM control methods should be represented by a number between 0 and 100, and can be thought of as a percentage. But some buggy _BQC/_BCL/_BCM methods use the index values instead. http://bugzilla.kernel.org/show_bug.cgi?id=12302 http://bugzilla.kernel.org/show_bug.cgi?id=12249 http://bugzilla.kernel.org/show_bug.cgi?id=12037 Add the functionality to support such kind of BIOSes in ACPI video driver. Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> --- drivers/acpi/video.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) Index: linux-2.6/drivers/acpi/video.c =================================================================== --- linux-2.6.orig/drivers/acpi/video.c +++ linux-2.6/drivers/acpi/video.c @@ -171,6 +171,9 @@ 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*/ + u8 _BCL_use_index:1; /* levels in _BCL are index values */ + u8 _BCM_use_index:1; /* input of _BCM is an index value */ + u8 _BQC_use_index:1; /* _BQC returns an index value */ }; struct acpi_video_device_brightness { @@ -505,7 +508,8 @@ acpi_video_device_lcd_set_level(struct a device->brightness->curr = level; for (state = 2; state < device->brightness->count; state++) if (level == device->brightness->levels[state]) { - device->backlight->props.brightness = state - 2; + if (device->backlight) + device->backlight->props.brightness = state - 2; return 0; } @@ -523,6 +527,13 @@ acpi_video_device_lcd_get_level_current( status = acpi_evaluate_integer(device->dev->handle, "_BQC", NULL, level); if (ACPI_SUCCESS(status)) { + if (device->brightness->flags._BQC_use_index) { + if (device->brightness->flags._BCL_reversed) + *level = device->brightness->count + - 3 - (*level); + *level = device->brightness->levels[*level + 2]; + + } device->brightness->curr = *level; return 0; } else { @@ -689,6 +700,7 @@ acpi_video_init_brightness(struct acpi_v { union acpi_object *obj = NULL; int i, max_level = 0, count = 0, level_ac_battery = 0; + unsigned long long level; union acpi_object *o; struct acpi_video_device_brightness *br = NULL; @@ -760,6 +772,38 @@ acpi_video_init_brightness(struct acpi_v br->count = count; device->brightness = br; + + /* Check the input/output of _BQC/_BCL/_BCM */ + if ((max_level < 100) && (max_level <= (count - 2))) + br->flags._BCL_use_index = 1; + + /* + * _BCM is always consistent with _BCL, + * at least for all the laptops we have ever seen. + */ + br->flags._BCM_use_index = br->flags._BCL_use_index; + + /* _BQC uses INDEX while _BCL uses VALUE in some laptops */ + if (acpi_video_device_lcd_set_level(device, max_level)) + goto out_free_levels; + + if (acpi_video_device_lcd_get_level_current(device, &level)) + goto out_free_levels; + + if ((level != max_level) && !br->flags._BCM_use_index) { + if (level_ac_battery != 2) { + /* + * For now, we don't support the _BCL like this: + * 16, 15, 0, 1, 2, 3, ..., 14, 15, 16 + * because we may mess up the index returned by _BQC. + * Plus: we have not got a box like this. + */ + ACPI_ERROR((AE_INFO, "_BCL not supported\n")); + goto out_free_levels; + } + br->flags._BQC_use_index = 1; + } + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count - 2)); kfree(obj); -- 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
