[lkml]   [2008]   [Apr]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    Subjectrc6+ regression - backlight reset to 0 on boot after 7c0ea45be4f114d85ee35caeead8e1660699c46f
    Commit 7c0ea45be4f114d85ee35caeead8e1660699c46f registers ACPI backlight
    even if _BQC method (query current backlight level) is missing. The effect is:

    during initialization video.c:acpi_video_device_find_cap() calls backlight_update_status(). It tries to fetch actual level via acpi_video_get_brightness() - but as _BQC is missing it just returns current value
    as stored in memory - i.e. zero, because it was never set. So effectively
    backlight_update_status() reset brightness to minimal value == 0.

    This happens on Toshiba Portege 4000. Verified by reverting commit on top of

    On a side note, it would be nice to fit backlight device into actual ACPI
    device tree instead of /devices/virtual.
    [unhandled content-type:application/pgp-signature]
     \ /
      Last update: 2008-04-02 20:57    [W:0.018 / U:28.964 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site