acpi: tie ACPI backlight devices to PCI devices if possible (9661e92c) · Commits · 戴 / test

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> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Tested-by:

Sedat Dilek <sedat.dilek@googlemail.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/acpi/video.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -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);

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