Dual-GPU machines may provide more than one ACPI backlight interface. Tie the backlight device to the GPU in order to allow userspace to identify the correct interface.
Signed-off-by: Matthew Garrett mjg@redhat.com --- drivers/acpi/video.c | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index a9eec8c..a18e497 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -782,6 +782,9 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
if (acpi_video_backlight_support()) { struct backlight_properties props; + struct pci_dev *pdev; + acpi_handle acpi_parent; + struct device *parent = NULL; int result; static int count = 0; char *name; @@ -794,10 +797,20 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) return; count++;
+ acpi_get_parent(device->dev->handle, &acpi_parent); + + pdev = acpi_get_pci_dev(acpi_parent); + if (pdev) { + parent = &pdev->dev; + pci_dev_put(pdev); + } + memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_FIRMWARE; props.max_brightness = device->brightness->count - 3; - device->backlight = backlight_device_register(name, NULL, device, + device->backlight = backlight_device_register(name, + parent, + device, &acpi_backlight_ops, &props); kfree(name);