Powertop makes wrong suggestion to add usbcore.autosuspend=1

[Nic]

Binary package hint: powertop

Powertop makes wrong suggestion to enable "usbcore autosuspend=1" if it finds device set to autosuspend=0.
According to documentation of "Power Management for USB" (, Alan Stern <email address hidden>, October 5, 2007. )
kernel, up version 2.6.22, use 0 for "autosuspend as soon as the device becomes idle" but -1 means never to autosuspend.
......
The user interface for dynamic PM
.....
 power/autosuspend

                This file contains an integer value, which is the
                number of seconds the device should remain idle before
                the kernel will autosuspend it (the idle-delay time).
                The default is 2. 0 means to autosuspend as soon as
                the device becomes idle, and -1 means never to
                autosuspend. You can write a number to the file to
                change the autosuspend idle-delay time.

Writing "-1" to power/autosuspend and writing "on" to power/level do
essentially the same thing -- they both prevent the device from being
autosuspended. Yes, this is a redundancy in the API.

(In 2.6.21 writing "0" to power/autosuspend would prevent the device
from being autosuspended; the behavior was changed in 2.6.22. The
power/autosuspend attribute did not exist prior to 2.6.21, and the
power/level attribute did not exist prior to 2.6.22.)

Regards,
Alex

[Evan Goers (megatog615)]

Confirmed. Here's what Powertop says in full:

"Suggestion: Enable USB autosuspend by pressing the U key or adding
usbcore.autosuspend=1 to the kernel command line in the grub config"

After adding it to the defoptions in my menu.list(and running update-grup), the kernel throws up a warning saying that usbcore.autosuspend doesn't exist.

[ɞєᾐ ἂ. (talkingwires)]

I'm running Gutsy, but am using Debian's 2.6.22 kernel package. Ubuntu's 2.6.22 kernel is broken for Netgear MA401 PCMCIA wireless users. Debian's works fine.

Anyway, I have been toying around with Powertop, and noticed a large increase in battery life when I allowed it to apply its suggestions. However, some of them might not be worth the price. Googling around to find a way to make the applied suggestions permanent, I found a thread (http://lists.openwall.net/linux-kernel/2007/08/03/316) from Red Hat users that indicated that USB Autosuspend breaks a lot of printers because their drivers do not support it. They even gave a backhand compliment to the Ubuntu developers for not implementing it.

Anyway, adding the line to my Grub config doesn't work, either, but maybe that's a good thing?

[ɞєᾐ ἂ. (talkingwires)]

I found another, Ubuntu-specific thread (http://www.nabble.com/USB-Problems-with-Ubuntu---workaround-t4260039.html) detailing problems with scanners and the USB Autosuspend function.

[Kansei (clauretano)]

It would still be nice for those of us who never attach USB printers or scanners to be able to implement this.

so where is the correct place?

[Evan Goers (megatog615)]

Maybe the Ubuntu devs knew about this problem and decided to disable it in the kernel?

[Matthew Garrett (mjg59)]

The powertop output is only relevant if the kernel has these drivers built in - we supply them as modules, so powertop should be fixed to provide more accurate information.

[Michael Adams (madams)]

On my Feisty router Dell PIII-1ghz with custom 2.6.22 kernel, the following commands appear to work based on suggestions from PowerTOP 1.8: I've added them to my /etc/init.d/rc.local.

echo 10 >/sys/bus/usb/devices/usb1/power/autosuspend
echo auto >/sys/bus/usb/devices/usb1/power/level

The commands are modified from a thread I found on the USB autosuspend (which were posted as commands to use with a .23 kernel).

http://www.gossamer-threads.com/lists/linux/kernel/822889

[midnightflash (midnightflash)]

"echo 10 >/sys/bus/usb/devices/usb1/power/autosuspend
echo auto >/sys/bus/usb/devices/usb1/power/level"
I added this too for every USB-port... but is doing nothing.

[Edwin Zeng (zyangxue)]

I saw the other way: add below line into /etc/modprobe.d/options
            options usbcore autosuspend=1
( Xubuntu 7.10 in my IBM T40, work perpectly)

[midnightflash (midnightflash)]

It's not working for me...
Still getting the message in PowerTop.
Ubuntu 7.10 - IBM R40 2722-3GG

[Xvani (fredrile+launchpad)]

No fixes working here either...
Bug confirmed.
Dell D420
Ubuntu 7.10

[Oleksij Rempel (olerem)]

this is a bug in powertop logic.
ubuntu kernel has usb autosuspend enabled by default, so you do not need any workarounds given here.

[midnightflash (midnightflash)]

@ fishor
Are you sure?
As far as I think it WAS enabled by default until 7.04 and IS changed to disabled by default from 7.10.

[Oleksij Rempel (olerem)]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

:~$ grep CONFIG_USB_SUSPEND /boot/config-2.6.22-14-generic
CONFIG_USB_SUSPEND=y

:~$ cat /sys/module/usbcore/parameters/autosuspend
2

:~$ cat /sys/bus/usb/devices/*/power/autosuspend
0
2
2
2
2
2

yes. it is enabled.

midnightflash schrieb:
> @ fishor
> Are you sure?
> As far as I think it WAS enabled by default until 7.04 and IS changed to disabled by default from 7.10.
>

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Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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ZbCeT4+M7Axe2x4SrOezrdA=
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[schmolch (saschaheid)]

There is something wrong here though.

Before i enable usb autosuspension with powertop my CPU (coreduo) is stuck in C2 75% of the time.
Only after pressing U to enable it the CPU stays in C3 97% of the time and the power-usage drops significantly.

[Javier Jardón (jjardon)]

See http://www.bughost.org/pipermail/power/2007-September/000992.html

Alan Jenkins wrote:
> Perhaps you have usbcore installed as a module? (CONFIG_USB=m). You can find
> out by checking for it in the output from lsmod. In that case you would want
> to change the modprobe configuration file, um... e.g. add
>
> options usbcore autosuspend=1
>
> to /etc/modprobe.d/options

[Oleksij Rempel (olerem)]

linux-2.6/Documentation/usb/power-management.txt
        power/autosuspend

                This file contains an integer value, which is the
                number of seconds the device should remain idle before
                the kernel will autosuspend it (the idle-delay time).
                The default is 2. 0 means to autosuspend as soon as
                the device becomes idle, and -1 means never to
                autosuspend. You can write a number to the file to
                change the autosuspend idle-delay time.

[Marco Rodrigues (gothicx)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. However, I am closing it because the bug has been fixed in the latest development version of Ubuntu - the Hardy Heron.

A backport for gutsy has been requested. Let's wait for it... Bug #172607

[Oleksij Rempel (olerem)]

Sorry. This is wrong fix.

1. This is not fixed upstream.
2. This fix is not according of any usb API documentation:
    - powertop version of logic: if autosuspend is less then 1 display suggestion. ( was made against old API and not correct for new API )
    - debian patch logic: if autosuspend is not 1 display suggestion. ( wrong at all )
    - should be: if autosuspend is negative ( -1, -2 ... ) display suggestion. ( will work for new API but not for old )

[Daniel Lombraña González (teleyinex)]

Hi,

Today I have found this entry: http://www.blackberryforums.com/linux-users-corner/97661-enable-disable-config_usb_suspend-s-autosuspend-mode.html and there they explain that if your USB devices have a value of 2 the kernel has suspended the usbcore. I have checked which is my default value of my Gutsy kernel and is 2, so powertop is not correctly detecting the state of usbcore, moreover if you check the /sys/bus/usb/devices/*/power/level you will get "auto" which means that the kernel is autosuspending the usb when it's necessary . Additionally it's not suggesting the right value to autosuspend the usb.

Daniel

[Wouter Stomp (wouterstomp-deactivatedaccount)]

This was correctly fixed in debian in 1.9-2. Needs a sync.

[schmolch (saschaheid)]

powertop (from svn) tells me that my CPU is stuck in C2 70% of the time until
- i enable usb-autosuspend with powertop
- or remove uhci_hcd myself.
after which C2 drops to zero.

At the same time cat /sys/bus/usb/devices/*/power/level reports AUTO for all values.
No usb-devices are used except for a internal fingerprint reader which is not set up (no modules loaded).
Kernel is 2.6.22-14-generic from Gutsy.

Can anyone explain this please?

[schmolch (saschaheid)]

0
2
2
2
2
2

are the wrong values, it needs to be

1
1
1
1
1
1

as suggested by powertop.

Its the only way to get the desired result, a SLEEPING Cpu.

[Greg A (etulfetulf)]

This has been fixed since Ubuntu Hardy.

[JoseLVG (josvazg)]

Then is broken again in Intrepid, at least in the eee kernel flavour.

(eee 901)

[Oleksij Rempel (olerem)]

It was newer fixed.
IMHO this suggestion should be removed, so nobody will complain about
it. autosuspend is enabled by default in the kernel and any
distribution overwrite this settings.

@Patrick
This is about powertop 1.10
you made notice:
   * Removed usb patch, source has changed completely. hopefully it was
fixed by upstream.
but the patch fix-suggest-usb-autosuspend.dpatch is steal there.

[Dimitrios Symeonidis (azimout)]

this is not fixed!

[Dimitrios Symeonidis (azimout)]

I did a little research to find the actual cause of the problem.

There's actually two issues here:

1) powertop suggests to add the usbcore.autosuspend=1 kernel parameter, but we're shipping usbcore as a module (solution described here: https://bugs.launchpad.net/ubuntu/+source/powertop/+bug/136549/comments/16)
this is a confirmed issue, and should be fixed

2) to decide whether to make this suggestion, powertop checks two things:
  a) that /sys/bus/usb/devices/*/power/autosuspend >=0
  b) that /sys/bus/usb/devices/*/power/level != “on”
I have found that in my machine the usb root hubs have power level = "auto", but slave devices (usb mouse, usb storage) have power lever = "on". this causes powertop to make this suggestion.
I am not sure whether powertop is right on this one (i.e. whether the power levels should be auto) or whether the current situation is correct, and powertop should change...

[hackel (hackel)]

I would like to confirm what Dimitrios said. In my case, I found:
/sys/bus/usb/devices/1-1/power/level = on
This device is my integrated webcam. Now the question is, what is the solution? I can set it to "auto" manually, of course (like in my rc.local), but is there no way to set it as the default for this device? I didn't see a way to set power/level as any module option, especially for a specific device.

[Dimitrios Symeonidis (azimout)]

The version included in Jaunty (1.11-1) includes the patch titled "fix-suggest-usb-autosuspend.dpatch
" (see https://edge.launchpad.net/ubuntu/+source/powertop), but the issue still exists, and the diff seems irrelevant (it changes the cdrom polling by hal, see: http://code.google.com/p/powertop/source/detail?r=301)

I am really confused...

[EricDHH (ericdhh)]

Linux calliope 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux

cat /home/eric# cat /sys/bus/usb/devices/usb1/power/level auto

ii powertop 1.11-1 Linux tool to find out what is using power

Vorschlag: Aktivieren Sie "USB autosuspend" durch drücken der U-Taste
oder durch Anhängen der Bootoption "usbcore.autosuspend=1" an die Kernel-
kommandozeile oder in der GRUB Konfiguration.

Confirmed, powertop already have this bug.

Bye
Eric

[Michał Gołębiowski-Owczarek (mgol)]

Still an issue.

[Michał Gołębiowski-Owczarek (mgol)]

$ uname -a
Linux mgol-laptop 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:05:01 UTC 2009 x86_64 GNU/Linux

$ cat /sys/bus/usb/devices/usb1/power/level
auto

$ apt-cache policy powertop
  Installed: 1.11-1ubuntu1

[kmsalex (alexmooer26)]

sorry guys, new to lunch pad, added this by mistake, can't figure out how to remove it.

[Alexander van Loon (avanloon)]

Changed it back to ‘new’ for you. You use the small icons next to the status to change it.

I wonder when this will be fixed? Launchpad claims the bug report on the Debian bug tracker is marked as fixed, so I guess when Ubuntu will synchronize with the Debian package for the next 10.10 release we should get the fix too. But when I read the bug report there I can’t see anywhere whether it’s fixed or not, nor when it would have been fixed.

[Elias K Gardner (zorkerz)]

I no longer experience this bug. Does anybody else or can we mark it as fixed?