[lkml]   [2011]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card
    On Fri, 2011-03-04 at 12:28 +0800, wrote: 
    > On Thu, 03 Mar 2011 16:05:50 PST, Greg KH said:
    > > > [ 0.818236] [Firmware Bug]: Duplicate ACPI video bus devices for the same VGA controller, please try module parameter "video.allow_duplicates=1"if the current driver doesn't work.
    > >
    > > Have you tried this option?
    > >
    > > There's nothing sysfs can do here, sorry, it really looks like you have
    > > a BIOS/firmware problem.
    this warning message is printed out because there are two ACPI devices
    for the same VGA controller, and Linux has no idea which can actually
    change the backlight.

    > Well, (a) it's been saying "try it if the current driver doesn't work" - and
    > things have worked just fine all along (or more properly, if it's broken in
    > behavior, I haven't actually seen the effects...)
    > and (b) Something changed very recently to add the WARNING, which wasn't there
    > in rc5-next-2011022.
    well. c504f8cb has been shipped in 2.6.33-rc5.
    can you attach the acpidump output of this machine please?
    please attach the dmesg output both with and without this warning.
    please attach the output of "grep . /sys/bus/acpi/drivers/video/*/path"
    in both kernels.

    > And (c) I doubt that's going to fix the WARNING, because looking at drivers/
    > acpi/video.c, the variable allow_duplicates is checked in exactly *ONE* place,
    > which is *after* the printk:
    > if (status == AE_ALREADY_EXISTS) {
    > printk(KERN_WARNING FW_BUG
    > "Duplicate ACPI video bus devices for the"
    > " same VGA controller, please try module "
    > "parameter \"video.allow_duplicates=1\""
    > "if the current driver doesn't work.\n");
    > if (!allow_duplicates)
    > return -ENODEV;
    > }
    > So since the warning triggers before we see the printk(), setting the variable
    > won't make a difference because we warn before we ever get into that if
    > statement.
    > Now, maybe we need to be checking allow_duplicates earlier and/or in other
    > places - but I'll let somebody who actually understands the code to decide taht. ;)

     \ /
      Last update: 2011-03-04 06:31    [W:0.024 / U:118.108 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site