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Subject: Re: usb-storage not recognizing archos 20g fm recorder in linux
From: Christian Mahr (
Date: 2003-10-27

Hi all,

I have observed that hotplugging my archos recorder 20 to Linux depends
sometimes on the sequence of what you do first:

        a) switch-on archos first, wait for complete power-up, then connect
        b) connect USB first, then power-on

As I overserved, option a) works much more reliable than b).

From my investigations (switching on tracing in usb-storage) in ealier kernel
versions I believe that during b) the USB interface in the archos is not
fully operable during boot, at a time linux already wants to access the disk.
So sometimes the first accesses to the disk fail on a
USB-block-exchange-level. On he other hand, until very recently, the re-tries
from linux side following an USB failure did not work in all of the possible
error scenarios. Such hang-ups can be be ovserved when you see usb-drivers in
"D" or "DW" state....

my current kernel version 2.4.23-pre7 seems to work best so far, but i did not
do a exhaustive research on this very recent kernel version.


Am Freitag, 24. Oktober 2003 20:30 schrieb John covici:
> Well I put the line in fstab and I got drivers and devices under
> /proc/bus/usb, but under devices there is nothing, under drivers
> there is usbdevfs usbhub and when I do the modprobe for usb-storage
> there is usb-storage but the device is still not detected.
> on Friday 10/24/2003 Alexandre Belloni( wrote
> > On Fri, Oct 24, 2003 at 10:39:59AM -0400, John covici wrote :
> > > What do you mean "mounted your usbfs" -- this is part of the /proc
> > > file system which of course is mounted.
> >
> > Do you have a line like that in your /etc/fstab ?
> >
> > none /proc/bus/usb usbfs defaults 0 0
> >
> > if not, usbfs is not mounted so there is nothing in /proc/bus/usb
> >
> > --
> > Alexandre Belloni
> > AE-UTBM: - - Lolut:
> > Key fingerprint = A7C6 7CD4 4328 59D1 79FD B8BB 945F 4DD5 B634 89BD

Christian Mahr (privat)        

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