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Re: USB bus fails to see devices



On Saturday 14 July 2007 18:55, Haines Brown wrote:
> Hugo Vanwoerkom <hvw59601@care2.com> writes:
>
> I'm not sure if Hugo was responding to my question or some other, but
> in any case, this allows me to ask a simple question or two.
>
> My problem was that the kernel stopped recognizing my camera (nothing
> appears in kernlog/syslog or lsusb), although all other USB devices
> are recognized.
>
> I gather that when a kernel is compiled, makeconfig will have a
> section for USB Support, which should be enabled, and a choice USB
> type (in my case is OHCI), a built in Preliminary USB device
> filesystem, and a choice of devices such as SB OV511 Camera
> support.
>
> However, my kernel config-2.6.18-4-686 has nothing of any of
> this. If these are part of kernel configuration, why don't I see them
> in the kernel config file?
>
> I'm told that USB support in the Linux kernel is buggy. Is
> it possible a kernel bug could cause it to miss my camera but still
> see all other USB devices? Is it likely my kernel would support my
> camera, and then for no obvious reason stop?
>
> If I were to reconfigure and recompile my kernel to enable
> CONFIG_USB_DEBUG, would I do that by changing
>
>         # CONFIG_USB_DEBUG is not set
> to
>         CONFIG_USB_DEBUG=y
>
> What would be the effect? Would I then get error messages in kernlog
> whenever the kernel tried but failed to see my camera? Would these
> messages definately tell me if the kernel were buggy?
>
> If my kernel were buggy, how would I know if there were a patch to fix
> the problem?
>
> When I was running sarge, I had a /proc/bus/usb/drivers directory on
> which was mounted usbdevfs, hub and usblp. The manual for The Linux
> USB Sub-System says that the usbdevfs must be mounted somewhere, and
> conventionally on /proc/bus/usb, and that it will hold a drivers
> pseudo-file. Has that changed under Etch? I don't have usbdevfs
> mounted anywhere ($ mount reports procbususb is mounted on
> /proc/bus/usb, although I see no procbususb file there). Wouldn't the
> absense of a mounted usbdevfs definitely interfere with the kernel's
> ability to see my camera?
>
> --
>
>        Haines Brown, KB1GRM

Just a thought, and I don't know which kernel you were using when all your usb 
devices were working ok, but I installed Debian from Woody disks which were 
upgraded to Sarge, and with the 2.6 kernel IIRC I had problems with my usb 
midi keyboard, and had to add to /etc/modules uhci_hcd. I see that that 
module isn't showing on your list.

Currently running Sarge, Etch, and Lenny. Only 2 devices on the USB though. 
The usb midi keyboard, and a webcam.

Nigel.




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