• Thomas Renninger's avatar
    ACPI video: if no ACPI backlight support, use vendor drivers · c3d6de69
    Thomas Renninger authored
    If an ACPI graphics device supports backlight brightness functions (cmp. with
    latest ACPI spec Appendix B), let the ACPI video driver control backlight and
    switch backlight control off in vendor specific ACPI drivers (asus_acpi,
    thinkpad_acpi, eeepc, fujitsu_laptop, msi_laptop, sony_laptop, acer-wmi).
    Currently it is possible to load above drivers and let both poke on the
    brightness HW registers, the video and vendor specific ACPI drivers -> bad.
    This patch provides the basic support to check for BIOS capabilities before
    driver loading time. Driver specific modifications are in separate follow up
    	Prever vendor driver over ACPI driver for backlight.
    "acpi_backlight=video" (default)
    	Prever ACPI driver over vendor driver for backlight.
    Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
    Acked-by: default avatarZhang Rui <rui.zhang@intel.com>
    Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
video_detect.c 8.36 KB