Ubuntu
linux-source-2.6.22 package

MacBook makes whining noise when uhci-hcd loaded

Bug #124642 reported by Tim Hull
0
Affects Status Importance Assigned to Milestone
Linux
Invalid
Undecided
Unassigned
linux-source-2.6.22 (Ubuntu)
Won't Fix
Undecided
Unassigned

Bug Description

Binary package hint: linux-image-2.6.22-7-generic

On my MacBook (first generation Core Duo) running Gutsy pre-release, I can hear a whining noise that first occurs when the uhci-hcd module is loaded on boot and persists until shutdown. This occurs on both the Gutsy and the Feisty kernels. However, I do NOT see this problem on Debian Etch (using a 2.6.18 kernel - I *do* see it on Etch with a 2.6.21 kernel), which leads me to believe that it was something introduced between 2.6.18 and 2.6.21.

Furthermore, the noise stops if I unload the uhci-hcd module - though, for obvious reasons, that makes the MacBook useless. Also, if I use the USB bus (i.e. copy music to my iPod), the noise stops for the period during which the USB bus is in use, but returns afterwards.

I have reported this upstream to lkml and the uhci maintainer, but wanted to make sure that this could get fixed in time for Gutsy.

Revision history for this message
Tim Hull (thully) wrote :

The instructions to limit ACPI power states (in particular limiting them to C1 and C2) at

http://www.thinkwiki.org/wiki/Problem_with_high_pitch_noises#Affected_Operating_Systems

seems to work around the issue. Dunno if there is a way to enable this for afflicted systems only...

Revision history for this message
Tim Hull (thully) wrote :

Upon further testing, it seems like the likely cause for this is 2.6.21+ having BETTER power management support - and, thus, entering the lower C-states. I did test disabling tickless operation, and it made the issue worse. I decided to close this because the issue also exists in Mac OS X and the lack of a problem in 2.6.18 seems like an aberration.

Changed in linux:
status: New → Invalid
Changed in linux-source-2.6.22:
status: New → Invalid
Revision history for this message
Tim Hull (thully) wrote :

OK - my bad. 2.6.18 was doing proper power management on Etch. Thus, I'm reopening this bug as it seems this CAN be worked around, though it is a hardware issue.

Changed in linux:
status: Invalid → Confirmed
Revision history for this message
Tim Hull (thully) wrote :

OK - my bad. 2.6.18 was doing proper power management on Etch. Thus, I'm reopening this bug as it seems this CAN be worked around, though it is a hardware issue.

Changed in linux-source-2.6.22:
status: Invalid → Confirmed
Revision history for this message
Matthew Garrett (mjg59) wrote :

Your bluetooth controller and trackpad are waking up the CPU regularly, which is what results in the noise. Disable bluetooth to improve this.

Changed in linux-source-2.6.22:
status: Confirmed → Won't Fix
Revision history for this message
Tim Hull (thully) wrote : Re: [Bug 124642] Re: MacBook makes whining noise when uhci-hcd loaded

I disabled bluetooth with:

hciconfig hci0 down

But the noise still happens as before. Any clue? Is there other modules I
have to unload?
I really want to know what the root of this issue is, mostly due to the fact
that 2.6.18 doesn't have the issue...
I know disabling C3/C4 stops it, but that isn't the root of it as
2.6.18goes into those states fine without the issue popping up.

Tim

P.S. How does one go about getting involved in Ubuntu development,
especially with regards to laptop and core system issues like (but not
necessarily identical to) this one? I've run into many issues along the way
and would like to help somewhat beyond simply reporting them

On 8/15/07, Matthew Garrett <email address hidden> wrote:
>
> Your bluetooth controller and trackpad are waking up the CPU regularly,
> which is what results in the noise. Disable bluetooth to improve this.
>
> ** Changed in: linux-source-2.6.22 (Ubuntu)
> Status: Confirmed => Won't Fix
>
> --
> MacBook makes whining noise when uhci-hcd loaded
> https://bugs.launchpad.net/bugs/124642
> You received this bug notification because you are a direct subscriber
> of the bug.
>

Tim Hull (thully)
Changed in linux:
status: Confirmed → Invalid
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