On Wed, 5 May 2004, Randy.Dunlap wrote:

> On Wed, 5 May 2004 23:11:10 -0500 Zariel Skotlex <[EMAIL PROTECTED]> wrote:
> 
> | Hi...
> |  I asked this a long time ago when I just got subscribed, but got no answer... I 
> guess I'll have to ask again and try to be specific/simpler this time.
> | 
> | When my kernel 2.6.5 tries to detect the modem, it goes on like this:
> | //---------------------------------------------------------------------------
> | usb 2-2: new full speed USB device using address 3
> | usb 2-2: new device strings: Mfr=1, Product=2, SerialNumber=3
> | ohci_hcd 0000:00:02.0: urb df530240 path 2 ep0in 82d60000 cc 8 --> status -75
> | drivers/usb/core/message.c: error getting string descriptor 0 (error=-75)
> | drivers/usb/core/message.c: USB device number 3 default language ID 0x409
> | ohci_hcd 0000:00:02.0: urb df530240 path 2 ep0in 82d60000 cc 8 --> status -75
> | drivers/usb/core/usb.c: usb_hotplug
> | usb 2-2: registering 2-2:1.0 (config #1, interface 0)
> | drivers/usb/core/usb.c: usb_hotplug
> | usb 2-2: registering 2-2:1.1 (config #1, interface 1)
> | drivers/usb/core/usb.c: usb_hotplug
> | usbnet 2-2:1.0: usb_probe_interface
> | usbnet 2-2:1.0: usb_probe_interface - got id
> | ohci_hcd 0000:00:02.0: urb df530240 path 2 ep0in 82d60000 cc 8 --> status -75
> | usbnet: probe of 2-2:1.0 failed with error -75
> | drivers/usb/core/usb.c: registered new driver usbnet
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | ohci_hcd 0000:00:02.0: urb df5a2c40 path 2 ep0in 82d60000 cc 8 --> status -75
> | //---------------------------------------------------------------------------
> | 
> | Pretty much says that my ohci_hcd driver couldn't probe the hardware.. and the 
> error code is -75 (what does -75 means anyway?). I've been having this problem since 
> 2.6.1, I think (it was working before... but strangely enough, my cable modem 
> stopped working the day I accidentally unplugged it... ever since then it won't 
> work. I tried connecting to other usb ports, I even got a new usb cable to no avail).
> 
> To look up USB error codes, first look at linux/include/asm-generic/errno*.h
> to find the value.  75 is EOVERFLOW in Linux.
> Now read linux/Documentation usb/error-codes.txt to see how linux-usb
> uses error codes.  EOVERFLOW means:
> 
> -EOVERFLOW (*)                The amount of data returned by the endpoint was
>                       greater than either the max packet size of the
>                       endpoint or the remaining buffer size.  "Babble".
> 
> and the (*) footnote says:
> 
> (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
> hardware problems such as bad devices (including firmware) or cables.
> 
> This has been our experience most of the time, so first guess is a
> suspect device.  It doesn't reply as expected, and possibly it's
> sending more data than was requested by linux-usb.
> This happens sometimes when linux-usb is trying to read descriptors
> from the device.  linux-usb often tries to read partial
> descriptors and some devices don't like that, even though it's
> allowed by the USB spec.
> 
> 
> | Strange thing is that the kernel 2.4.25 has no problems loading my cable modem, 
> EXCEPT after rebooting from a 2.6 kernel, when I do a 2.6-> 2.4 change, my cable 
> modem also fails to be detected!
> 
> Oh.  So this represents some kind of regression in linux-usb, eh?
> Could you try Linux-2.6.6-rc3?  (hopefully 2.6.6 will be out soon
> and you can test it)
> 
> Alan, any thoughts about this one?
> It seems that Zariel thinks it is OHCI-related, so you wouldn't be
> the right person for that, but it seems more related to
> descriptor parsing to me.  Of course, that is just a guess.

It might not be related to OHCI; it might have more to do with the way the 
modem is initialized by usbcore.  Clearly this is more than just a 
descriptor-parsing problem, because -EOVERFLOW shouldn't ever happen 
unless something is wrong with either the host hardware or the device.

A good test, if Zariel can do it, would be to try using a different 
computer, maybe even one with a UHCI controller.

Alan Stern



-------------------------------------------------------
This SF.Net email is sponsored by Sleepycat Software
Learn developer strategies Cisco, Motorola, Ericsson & Lucent use to 
deliver higher performing products faster, at low TCO.
http://www.sleepycat.com/telcomwpreg.php?From=osdnemail3
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-users

Reply via email to