sean finney on 19 Jan 2004 00:23:02 -0000


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Re: [PLUG] Problem with USB Flash Disk


heya,

On Sun, Jan 18, 2004 at 06:05:20PM -0500, W. Chris Shank wrote:
> I've highluighted the difference below. Basically, your system is
> running USB 1.1 not USB 2.0 - which is why I was able to use it on an
> older computer as well.

yeah, i see that now.  i saw

> > D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1

and thought that was usb 2.0, not seeing the speed was set to
1.1 'full speed' @ 12mbps.  turns out i'm using usb-uhci (as
you could tell from my dmesg), but i guess i need to use the
ehci driver for 2.0 support, assuming my hardware actually
supports it (i'm researching this right now).

> It may be due to the device identifiers not being in the hotplug
> mappings as someone olse suggested - but I think it's odd that it would
> work in USB 1.1 mode but not USB 2.0 mode - as the identifiers aren't
> changing between modes (as far as I could tell).

could be.  i've also read that usb 2.0 support in 2.4 series kernel's
isn't all that great.  not only are there more bugs, but apparently
you still can't get much faster than 10mbps bandwidth due to the
i/o scheduling for usb devices in 2.4[1].  

On Sun, Jan 18, 2004 at 06:17:00PM -0500, W. Chris Shank wrote:
> However, the lack of floppy could be causing the issue - if I boot with
> the USB drive plugged in I get an error as if there is a floppy disk
> with an unbootable disk inserted - I need to remove the USB drive and
> retry.

you mean your laptop can boot off of the usb drive?  that's cool. 
bootstrap your favorite linux distro onto your usb drive and you
have a nice rescue disk :)

to try to see if it is a problem with the lack of a floppy drive, try
modprobe'ing your floppy driver before putting the drive in, that might
skip the floppy check.  you could also try temporarily disabling your
hotplug service and do everything manually to see if it's a problem
with hotplug like you suspect.

in the meantime, i'm going to try compiling myself a 2.6 kernel (and
maybe a 2.4.24 kernel too) with the ehci support too see if i can
get 2.0 support myself.


	sean



[1] i found some good reading for this at
    http://www.linux-usb.org/usb2.html

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