diff options
Diffstat (limited to 'drivers/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 05dff631591..b765790b32b 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -78,6 +78,13 @@ MODULE_LICENSE("GPL"); static int brightness_switch_enabled = 1; module_param(brightness_switch_enabled, bool, 0644); +/* + * By default, we don't allow duplicate ACPI video bus devices + * under the same VGA controller + */ +static int allow_duplicates; +module_param(allow_duplicates, bool, 0644); + static int register_count = 0; static int acpi_video_bus_add(struct acpi_device *device); static int acpi_video_bus_remove(struct acpi_device *device, int type); @@ -999,8 +1006,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) sprintf(name, "acpi_video%d", count++); device->backlight = backlight_device_register(name, NULL, device, &acpi_backlight_ops); - device->backlight->props.max_brightness = device->brightness->count-3; kfree(name); + if (IS_ERR(device->backlight)) + return; + device->backlight->props.max_brightness = device->brightness->count-3; result = sysfs_create_link(&device->backlight->dev.kobj, &device->dev->dev.kobj, "device"); @@ -1979,6 +1988,10 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event) unsigned long long level_current, level_next; int result = -EINVAL; + /* no warning message if acpi_backlight=vendor is used */ + if (!acpi_video_backlight_support()) + return 0; + if (!device->brightness) goto out; @@ -2233,11 +2246,47 @@ static int acpi_video_resume(struct acpi_device *device) return AE_OK; } +static acpi_status +acpi_video_bus_match(acpi_handle handle, u32 level, void *context, + void **return_value) +{ + struct acpi_device *device = context; + struct acpi_device *sibling; + int result; + + if (handle == device->handle) + return AE_CTRL_TERMINATE; + + result = acpi_bus_get_device(handle, &sibling); + if (result) + return AE_OK; + + if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME)) + return AE_ALREADY_EXISTS; + + return AE_OK; +} + static int acpi_video_bus_add(struct acpi_device *device) { struct acpi_video_bus *video; struct input_dev *input; int error; + acpi_status status; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, + device->parent->handle, 1, + acpi_video_bus_match, NULL, + device, NULL); + if (status == AE_ALREADY_EXISTS) { + printk(KERN_WARNING FW_BUG + "Duplicate ACPI video bus devices for the" + " same VGA controller, please try module " + "parameter \"video.allow_duplicates=1\"" + "if the current driver doesn't work.\n"); + if (!allow_duplicates) + return -ENODEV; + } video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL); if (!video) |