mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card

mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card

[Valdis.Kletnieks]

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On Wed, 02 Mar 2011 16:52:55 PST, akpm@linux-foundation.org said:
> The mm-of-the-moment snapshot 2011-03-02-16-52 has been uploaded to
> 
>    http://userweb.kernel.org/~akpm/mmotm/

Dell Latitude E6500, with an NVidia G98M (Quadro NVS 160M) graphics card.

Seen in my dmesg - it's had the 'Firmware Bug' message for roughly forever, but
apparently somewhere recently a warning crawled in. 2.6.38-rc5-next-20110222
did not throw the warning, jsut the firmware bug msg.

Hope somebody recognizes it, I won't be able to bisect this one for a bit (I
have 2 or 3 other things I have a bigger need to track down).

[    0.784712] ACPI: Sleep Button [SBTN]
[    0.816626] ------------[ cut here ]------------
[    0.816633] WARNING: at fs/sysfs/dir.c:455 sysfs_add_one+0x88/0x9c()
[    0.816635] Hardware name: Latitude E6500                  
[    0.816637] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0/device'
[    0.816640] Modules linked in:
[    0.816645] Pid: 1, comm: swapper Not tainted 2.6.38-rc7-mmotm0302 #2
[    0.816647] Call Trace:
[    0.816652]  [<ffffffff8103899e>] ? warn_slowpath_common+0x7e/0x96
[    0.816657]  [<ffffffff81038a4a>] ? warn_slowpath_fmt+0x41/0x43
[    0.816661]  [<ffffffff8114d876>] ? sysfs_add_one+0x88/0x9c
[    0.816665]  [<ffffffff8114e06e>] ? sysfs_do_create_link+0x145/0x1d5
[    0.816669]  [<ffffffff8114e10c>] ? sysfs_create_link+0xe/0x10
[    0.816674]  [<ffffffff8126cef1>] ? acpi_video_device_find_cap+0x1f5/0x2de
[    0.816678]  [<ffffffff8126d196>] ? acpi_video_bus_get_one_device+0x1bc/0x250
[    0.816682]  [<ffffffff8126d3f8>] ? acpi_video_bus_add+0x1ce/0x36e
[    0.816687]  [<ffffffff8124983d>] ? acpi_device_probe+0x49/0x117
[    0.816692]  [<ffffffff812bd56b>] ? really_probe+0xc0/0x14d
[    0.816696]  [<ffffffff812bd6fe>] ? driver_probe_device+0x37/0x52
[    0.816700]  [<ffffffff812bd773>] ? __driver_attach+0x5a/0x7d
[    0.816704]  [<ffffffff812bd719>] ? __driver_attach+0x0/0x7d
[    0.816708]  [<ffffffff812bc85d>] ? bus_for_each_dev+0x54/0x88
[    0.816712]  [<ffffffff812bd319>] ? driver_attach+0x19/0x1b
[    0.816715]  [<ffffffff812bcf6d>] ? bus_add_driver+0xab/0x201
[    0.816719]  [<ffffffff812bd976>] ? driver_register+0xb2/0x11f
[    0.816724]  [<ffffffff81b3cf29>] ? acpi_video_init+0x0/0x17
[    0.816729]  [<ffffffff8124a29e>] ? acpi_bus_register_driver+0x3e/0x40
[    0.816732]  [<ffffffff8126c8c5>] ? acpi_video_register+0x1b/0x34
[    0.816736]  [<ffffffff81b3cf3e>] ? acpi_video_init+0x15/0x17
[    0.816741]  [<ffffffff8100020a>] ? do_one_initcall+0x7a/0x130
[    0.816746]  [<ffffffff81b1bc0e>] ? kernel_init+0xe1/0x15b
[    0.816750]  [<ffffffff81002f94>] ? kernel_thread_helper+0x4/0x10
[    0.816754]  [<ffffffff8102a634>] ? finish_task_switch+0x3f/0xe3
[    0.816759]  [<ffffffff8155ab44>] ? restore_args+0x0/0x30
[    0.816763]  [<ffffffff81b1bb2d>] ? kernel_init+0x0/0x15b
[    0.816766]  [<ffffffff81002f90>] ? kernel_thread_helper+0x0/0x10
[    0.816804] ---[ end trace 6d450e935ee1897c ]---
[    0.816808] ACPI: Create sysfs link
[    0.817274] acpi device:38: registered as cooling_device0
[    0.818068] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A03:00/device:36/LNXVIDEO:00/input/input3
[    0.818077] ACPI: Video Device [VID] (multi-head: yes  rom: no  post: no)
[    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.
[    0.818369] ACPI: acpi_idle registered with cpuidle




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Re: mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card

[Greg KH]

On Thu, Mar 03, 2011 at 06:50:41PM -0500, Valdis.Kletnieks@vt.edu wrote:
> On Wed, 02 Mar 2011 16:52:55 PST, akpm@linux-foundation.org said:
> > The mm-of-the-moment snapshot 2011-03-02-16-52 has been uploaded to
> > 
> >    http://userweb.kernel.org/~akpm/mmotm/
> 
> Dell Latitude E6500, with an NVidia G98M (Quadro NVS 160M) graphics card.
> 
> Seen in my dmesg - it's had the 'Firmware Bug' message for roughly forever, but
> apparently somewhere recently a warning crawled in. 2.6.38-rc5-next-20110222
> did not throw the warning, jsut the firmware bug msg.
> 
> Hope somebody recognizes it, I won't be able to bisect this one for a bit (I
> have 2 or 3 other things I have a bigger need to track down).
> 
> [    0.784712] ACPI: Sleep Button [SBTN]
> [    0.816626] ------------[ cut here ]------------
> [    0.816633] WARNING: at fs/sysfs/dir.c:455 sysfs_add_one+0x88/0x9c()
> [    0.816635] Hardware name: Latitude E6500                  
> [    0.816637] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0/device'
> [    0.816640] Modules linked in:
> [    0.816645] Pid: 1, comm: swapper Not tainted 2.6.38-rc7-mmotm0302 #2
> [    0.816647] Call Trace:
> [    0.816652]  [<ffffffff8103899e>] ? warn_slowpath_common+0x7e/0x96
> [    0.816657]  [<ffffffff81038a4a>] ? warn_slowpath_fmt+0x41/0x43
> [    0.816661]  [<ffffffff8114d876>] ? sysfs_add_one+0x88/0x9c
> [    0.816665]  [<ffffffff8114e06e>] ? sysfs_do_create_link+0x145/0x1d5
> [    0.816669]  [<ffffffff8114e10c>] ? sysfs_create_link+0xe/0x10
> [    0.816674]  [<ffffffff8126cef1>] ? acpi_video_device_find_cap+0x1f5/0x2de
> [    0.816678]  [<ffffffff8126d196>] ? acpi_video_bus_get_one_device+0x1bc/0x250
> [    0.816682]  [<ffffffff8126d3f8>] ? acpi_video_bus_add+0x1ce/0x36e
> [    0.816687]  [<ffffffff8124983d>] ? acpi_device_probe+0x49/0x117
> [    0.816692]  [<ffffffff812bd56b>] ? really_probe+0xc0/0x14d
> [    0.816696]  [<ffffffff812bd6fe>] ? driver_probe_device+0x37/0x52
> [    0.816700]  [<ffffffff812bd773>] ? __driver_attach+0x5a/0x7d
> [    0.816704]  [<ffffffff812bd719>] ? __driver_attach+0x0/0x7d
> [    0.816708]  [<ffffffff812bc85d>] ? bus_for_each_dev+0x54/0x88
> [    0.816712]  [<ffffffff812bd319>] ? driver_attach+0x19/0x1b
> [    0.816715]  [<ffffffff812bcf6d>] ? bus_add_driver+0xab/0x201
> [    0.816719]  [<ffffffff812bd976>] ? driver_register+0xb2/0x11f
> [    0.816724]  [<ffffffff81b3cf29>] ? acpi_video_init+0x0/0x17
> [    0.816729]  [<ffffffff8124a29e>] ? acpi_bus_register_driver+0x3e/0x40
> [    0.816732]  [<ffffffff8126c8c5>] ? acpi_video_register+0x1b/0x34
> [    0.816736]  [<ffffffff81b3cf3e>] ? acpi_video_init+0x15/0x17
> [    0.816741]  [<ffffffff8100020a>] ? do_one_initcall+0x7a/0x130
> [    0.816746]  [<ffffffff81b1bc0e>] ? kernel_init+0xe1/0x15b
> [    0.816750]  [<ffffffff81002f94>] ? kernel_thread_helper+0x4/0x10
> [    0.816754]  [<ffffffff8102a634>] ? finish_task_switch+0x3f/0xe3
> [    0.816759]  [<ffffffff8155ab44>] ? restore_args+0x0/0x30
> [    0.816763]  [<ffffffff81b1bb2d>] ? kernel_init+0x0/0x15b
> [    0.816766]  [<ffffffff81002f90>] ? kernel_thread_helper+0x0/0x10
> [    0.816804] ---[ end trace 6d450e935ee1897c ]---
> [    0.816808] ACPI: Create sysfs link
> [    0.817274] acpi device:38: registered as cooling_device0
> [    0.818068] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A03:00/device:36/LNXVIDEO:00/input/input3
> [    0.818077] ACPI: Video Device [VID] (multi-head: yes  rom: no  post: no)
> [    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.

good luck,

greg k-h

Re: mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card

[Valdis.Kletnieks]

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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.

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.

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. ;)

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Re: mmotm 2011-03-02 - ACPI/sysfs WARNING with NVidia graphics card

[Zhang Rui]

On Fri, 2011-03-04 at 12:28 +0800, Valdis.Kletnieks@vt.edu 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.
> 
right.
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. ;)