lkml.org 
[lkml]   [2003]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [linux-usb-devel] [BUG] Still having problems with an USB Drive
On Thu, 13 Nov 2003, Rogério Brito wrote:

> Yes, thinking more about the problem, that seems to be the case. David
> Brownell already told me that.
>
> I sent him an e-mail telling what I see when I modify my
> /etc/hotplug/usb.rc script to contain "modprobe -q uhci-hcd debug=2".

An alternative is after you have loaded uhci-hcd but before your device is
plugged in, do

echo 4 > /proc/driver/uhci/...

where ... is the file corresponding to the controller you plug your device
into. Debugging level 4 will provide more information than level 2, in
any case.

> > Forget about usb-storage and hotplug scripts. If you can't even get
> > to the point where your device show up in /proc/bus/usb/devices then
> > nothing else will work.
>
> Yes, the strange thing is that sometimes, the drive is detected and it
> works. Sometimes, it doesn't. Most of the time, it doesn't. And when
> it doesn't work and I try to turn hotplug off, I get unkillable
> processes (khubd is in state D).
>
> Anyway, what should I do? Should I just boot into single user mode
> without hotplug enabled and load the modules by hand?

That would be a good way of testing.

> > Judging from your dmesg output, you have an external hub (ALCOR
> > Generic USB Hub) into which your device is plugged. The device
> > contains an internal hub (Leading Driver Co., LTD. USB Embedded Hub)
> > and the drive is attached through that internal hub.
>
> I don't really know much about my USB setup. I have an Asus A7V
> motherboad and according to its manual (which I just checked), it has 2
> USB ports and two USB "leads" (in one of those, I plugged a small cable
> to a daughterboard, which gives me more USB ports).
>
> Perhaps this small daughterboard is a new hub?

Judging from your latest dmesg postings, it is.

> Anyway, it seems that I have problems regardless of which port I connect
> my USB drive to. But I can make tests to confirm that if anybody tells
> me what to do.
>
> Oh, BTW, Leading Driver is the USB drive (perhaps it's an internal hub
> in the drive?). It may be recognized as more than just one USB device,
> but I'm not certain of that, since I don't know what I'm talking about.

It definitely is getting recognized as more than one USB device, but
that's the point where things go wrong.

> > But an attempt to communicate with the drive failed. It could be a
> > problem with the external hub, the internal hub, or the drive itself;
> > it's not likely to be a problem with the kernel. The error message
>
> Ok.
>
> > hub 2-2.2:1.0: transfer --> -75
> >
> > indicates a problem with the internal hub, but there's no way to tell what
> > that problem is. The other error message
>
> Is there any way to discover what may be the reason of the problem? Any
> higher debugging level would help with that?

The only way I can think of is by comparison with what happens when the
device works. That's why I suggested trying another computer. Another
approach would be to use a USB logging programs to see what happens when
you use your device under Windows.

> > usb 2-2.2.1: control timeout on ep0in
> >
> > indicates a problem communicating with the drive, but that could be caused
> > by the internal hub not working right.
>
> Right.

Also, if you can collect and post the dmesg output from one of those
occasions when the device does work, perhaps that will help.

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:58    [W:0.065 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site