Messages in this thread | | | Date | Sat, 7 Jul 2007 22:17:34 -0400 (EDT) | From | Alan Stern <> | Subject | Re: PROBLEM: MacBook makes whining noise when usb-uhci active |
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On Sat, 7 Jul 2007, Tim Hull wrote:
> [1.] One line summary of the problem: MacBook makes whining noise when > usb-uhci loaded.
I assume you mean uhci-hcd. usb-uhci is part of Linux 2.4, not 2.6.
> [2.] Full description of the problem/report: On my MacBook (first generation > Core Duo 1.83GHz), I can hear a faint whining noise that becomes audible > when usb-uhci is loaded and remains audible except when the USB ports are in > use (i.e. the noise temporarily stops when I'm copying music to my iPod).
You have a USB keyboard, right? So the ports are always in use -- unless you unplug the keyboard.
> This problem occurs on both 2.6.21 and 2.6.22-rc7, but does not occur on > 2.6.18. Unloading usb-uhci when booted in 2.6.22-rc7 makes the whining > noise stop, but the system is useless in this state for obvious reasons. > The same whine does occur in OS X that occurs in 2.6.22-rc7 (though it does > NOT occur in 2.6.18)
I don't know what's causing the noise. Maybe something operating at the UHCI controller's 1000-Hz frame rate is coupling to a speaker connection.
Anyway it's clearly a hardware problem, even if it is triggered by something in software. About all I can suggest is to surround the MacBook with something sound-absorbent. (Not very helpful, I agree.)
Alan Stern
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