• Daniel Drake's avatar
    Revert "ACPI / battery: Add quirk for Asus GL502VSK and UX305LA" · 82bf43b2
    Daniel Drake authored
    Revert commit c68f0676 ("ACPI / battery: Add quirk for Asus
    GL502VSK and UX305LA") and commit 4446823e ("ACPI / battery: Add
    quirk for Asus UX360UA and UX410UAK").
    
    On many many Asus products, the battery is sometimes reported as
    charging or discharging even when it is full and you are on AC power.
    This change quirked the kernel to avoid advertising the discharging
    state when this happens on 4 laptop models, under the belief that
    this was incorrect information.  I presume it originates from user
    reports who are confused that their battery status icon says that it
    is discharging.
    
    However, the reported information is indeed correct, and the quirk
    approach taken is inadequate and more thought is needed first.
    Specifically:
    
     1. It only quirks discharging state, not charging
    
     2. There are so many different Asus products and DMI naming variants
        within those product families that behave this way; Linux could
        grow to quirk hundreds of products and still not even be close at
        "winning" this battle.
    
     3. Asus previously clarified that this behaviour is intentional. The
        platform will periodically do a partial discharge/charge cycle
        when the battery is full, because this is one way to extend the
        lifetime of the battery (leaving a battery at 100% charge and
        unused will decrease its usable capacity over time).
    
        My understanding is that any decent consumer product will have
        this behaviour, but it appears that Asus is different in that
        they expose this info through ACPI.
    
        However, the behaviour seems correct. The ACPI spec does not
        suggest in that the platform should hide the truth.  It lets you
        report that the battery is full of charge, and discharging, and
        with external power connected; and Asus does this.
    
     4. In terms of not confusing the user, this seems like something that
        could/should be handled by userspace, which can also detect these
        same (accurate) conditions in the general case.
    
    Revert this quirk before it gets included in a release, while we look
    for better approaches.
    Signed-off-by: default avatarDaniel Drake <drake@endlessm.com>
    Acked-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    82bf43b2
battery.c 39 KB