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> Acked-by: Matthew Garrett <mjg59@xxxxxxxxxxxxx> Acked-by: Thomas Renninger <trenn@xxxxxxx> --- drivers/acpi/video.c | 91 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 70 insertions(+), 21 deletions(-) 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 { @@ -689,8 +700,10 @@ 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, level_old; union acpi_object *o; struct acpi_video_device_brightness *br = NULL; + int result = -EINVAL; if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available " @@ -704,13 +717,16 @@ acpi_video_init_brightness(struct acpi_v br = kzalloc(sizeof(*br), GFP_KERNEL); if (!br) { printk(KERN_ERR "can't allocate memory\n"); + result = -ENOMEM; goto out; } br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels), GFP_KERNEL); - if (!br->levels) + if (!br->levels) { + result = -ENOMEM; goto out_free; + } for (i = 0; i < obj->package.count; i++) { o = (union acpi_object *)&obj->package.elements[i]; @@ -756,10 +772,55 @@ 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 */ + br->curr = max_level; + result = acpi_video_device_lcd_get_level_current(device, &level_old); + if (result) + goto out_free_levels; + + result = acpi_video_device_lcd_set_level(device, br->curr); + if (result) + goto out_free_levels; + + result = acpi_video_device_lcd_get_level_current(device, &level); + if (result) + goto out_free_levels; + + if ((level != level_old) && !br->flags._BCM_use_index) { + /* Note: + * This piece of code does not work correctly if the current + * brightness levels is 0. + * But I guess boxes that boot with such a dark screen are rare + * and no mroe code is needed to cover this specifial case. + */ + + 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")); + } + br->flags._BQC_use_index = 1; + } + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count - 2)); kfree(obj); - return max_level; + return result; out_free_levels: kfree(br->levels); @@ -768,7 +829,7 @@ out_free: out: device->brightness = NULL; kfree(obj); - return 0; + return result; } /* @@ -785,7 +846,6 @@ out: static void acpi_video_device_find_cap(struct acpi_video_device *device) { acpi_handle h_dummy1; - u32 max_level = 0; memset(&device->cap, 0, sizeof(device->cap)); @@ -814,13 +874,14 @@ static void acpi_video_device_find_cap(s device->cap._DSS = 1; } - if (acpi_video_backlight_support()) - max_level = acpi_video_init_brightness(device); - - if (device->cap._BCL && device->cap._BCM && max_level > 0) { + if (acpi_video_backlight_support()) { int result; static int count = 0; char *name; + + result = acpi_video_init_brightness(device); + if (result) + return; name = kzalloc(MAX_NAME_LEN, GFP_KERNEL); if (!name) return; @@ -829,18 +890,6 @@ static void acpi_video_device_find_cap(s device->backlight = backlight_device_register(name, NULL, device, &acpi_backlight_ops); device->backlight->props.max_brightness = device->brightness->count-3; - /* - * If there exists the _BQC object, the _BQC object will be - * called to get the current backlight brightness. Otherwise - * the brightness will be set to the maximum. - */ - if (device->cap._BQC) - device->backlight->props.brightness = - acpi_video_get_brightness(device->backlight); - else - device->backlight->props.brightness = - device->backlight->props.max_brightness; - backlight_update_status(device->backlight); kfree(name); device->cdev = thermal_cooling_device_register("LCD", -- 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
