Original the i915 driver called acpi_video_register(), but that was
replaced with acpi_video_register_with_quirks(), which we can not
backport easily, replace it with the old call to
acpi_video_register() again.
Thos backports the following commit:
commit
8c5bd7adb2ce47e6aa39d17b2375f69b0c0aa255
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date: Thu Jul 18 02:08:06 2013 +0200
ACPI / video / i915: No ACPI backlight if firmware expects Windows 8
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
--- /dev/null
+#ifndef __BACKPORT_ACPI_VIDEO_H
+#define __BACKPORT_ACPI_VIDEO_H
+#include_next <acpi/video.h>
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,12,0)
+static inline int acpi_video_register_with_quirks(void)
+{
+ return acpi_video_register();
+}
+#endif
+
+#endif /* __BACKPORT_ACPI_VIDEO_H */