[PATCH 08/32] acpi-video-detect: Unregister acpi_video backlight when dmi quirks are added

Hans de Goede hdegoede at redhat.com
Wed Jun 10 06:01:08 PDT 2015

Make acpi_video_set_dmi_backlight_type() call
acpi_video_unregister_backlight() when the new dmi quirk results in
the desired backlight interface being of a type other then

This avoid the need for the second if in the following construction
which is currently found in many platform/x86 drivers:

	if (prefer_vendor_quirk)

	if (!acpi_video_backlight_support())

This second if-block will be removed from the platform drivers as part
of their conversion to the new backlight interface selection API.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
 drivers/acpi/video_detect.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 01c8c46..98368cf 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -187,6 +187,9 @@ EXPORT_SYMBOL(acpi_video_get_backlight_type);
 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
 	acpi_backlight_dmi = type;
+	/* Remove acpi-video backlight interface if it is no longer desired */
+	if (acpi_video_get_backlight_type() != acpi_backlight_video)
+		acpi_video_unregister_backlight();

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