Strange USB Scaner Problem
norman at littletank.org
Tue May 22 16:37:35 UTC 2007
< snip >
> Interestingly enough, this problem is listed in both the Edgy and Feisty
> pages for http://ubuntuguide.org/wiki/Ubuntu:Feisty see:
> and for Edgy:
> Workaround for random device disconnections
> Random disconnection is a kernel bug that is not fixed yet. Some users
> report randomly disconnecting USB devices, especially external hard
> drives. One solution is to start the system with the option "irqpoll" in
> grub, but this doesn't work for everybody, and is believed to make the
> whole system slower. The other solution is to disable USB 2.0. This will
> result in way slower read/write, but the connection remains stable.
> To disable USB 2.0, type this in the terminal:
> sudo modprobe -r ehci_hcd
> Test if the copy/write process is stable, and if you want to disable USB
> 2.0 upon boot, type:
> sudo sh -c 'echo blacklist ehci_hcd > /etc/modprobe.d/blacklist-ehci'
> sudo update-initramfs -u -k `uname -r`
> Perhaps the reason that I am not having problems with the scanner on my
> Canon MP750 is that I have no USB 2 ports - all of my ports are USB 1.1.
This seems most encouraging, I will give it a try. I presume that if it
does not work a reboot will return the system to how it was.
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