Re: Problems writing to USB devices

["J. Scott Kasten" <jscottkasten@yahoo.com>]

On Wed, 17 Oct 2007, Giuseppe Sacco wrote:

> Hi all, I am still testing new kernels on the ip32 platform (and 
> learning kernel structure :-)). Currently I found problems in writing to 
> USB block devices. I may read from a pendrive without problem, but when 
> I try to write the process stop. This is the last part of a transcript 
> of strace output for "pvcreate /dev/sdc" command:
>

A few questions...

* Which USB card, or more precisely, which chipset is on the USB card you 
picked?

I've had great luck with NEC and ALI chips thus far.

* Which driver was loaded for the USB controller, OHCI, UHCI, EHCI?

If you have a USB 2.0 controller, the system will probably try to load 
both EHCI and UHCI.  I did run into problems there, for one, the system 
crashed when I pulled the thumb drive out.  It sometimes behaved strangely 
when it was in.  I eventually figured out that removing UHCI and running 
EHCI only was the solution for me.  The UHCI module seemed to be probing 
the hardware incorrectly.  It was reporting 6 ports on the bridge when 
there were only 2.  The EHCI module was reporting the correct number as I 
recall.  Once it was EHCI only, I've never had a problem since.

That was originally under 2.6.17 from gentoo.  I've since been using the 
debian patched 2.6.18.  I'm afraid I haven't yet reached sufficient 
motivation to move into the 20's like the rest of you.  I tend to like my 
box working...  :)  Just joking.....it's on the todo list.

-S-