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  • * Re: PROBLEM: MacBook makes whining noise when usb-uhci active
           [not found] <9a7c669e0707071551v2705320dn876ad208fa60a537@mail.gmail.com>
           [not found] ` <9a7c669e0707071554wcd74b59j94464c60f32f7ddd@mail.gmail.com>
    @ 2007-07-08  2:17 ` Alan Stern
      2007-07-08  2:54   ` Gerald Britton
      1 sibling, 1 reply; 8+ messages in thread
    From: Alan Stern @ 2007-07-08  2:17 UTC (permalink / raw)
      To: Tim Hull; +Cc: linux-kernel
    
    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
    
    
    ^ permalink raw reply	[flat|nested] 8+ messages in thread

  • end of thread, other threads:[~2007-07-08 12:54 UTC | newest]
    
    Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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         [not found] <9a7c669e0707071551v2705320dn876ad208fa60a537@mail.gmail.com>
         [not found] ` <9a7c669e0707071554wcd74b59j94464c60f32f7ddd@mail.gmail.com>
    2007-07-07 23:45   ` PROBLEM: MacBook makes whining noise when usb-uhci active Tim Hull
    2007-07-08  0:24     ` Richard Mittendorfer
    2007-07-08  2:17 ` Alan Stern
    2007-07-08  2:54   ` Gerald Britton
    2007-07-08  4:27     ` Henrique de Moraes Holschuh
    2007-07-08  4:41       ` Tim Hull
    2007-07-08 11:58         ` Carlo Wood
    2007-07-08 12:54           ` Henrique de Moraes Holschuh
    

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