Alan Stern wrote:
This debugfs is very interesting. I had not heard of it before but it
can be very usefull. I had already CONFIG_USB_DEBUG enabled, but
yesterday I have built a kernel with debugfs enabled as well.
Unfortunately no OHCI showed up, I had it mounted in /sys/kernel/debug.
The location of those debugging files has changed over time. Since
you're using an old version of the kernel, you should find them under
/sys/class/usb_host/usb_hostN/, where N is the bus number of the
controller.
Aha, that is good to know. When looking on the web, I had not found that.
I'll probably come back to this list (and in any case I'll send you a pm
if I solve it). I would still highly appreciate it if you could tell me
what the basic trigger of the disconnection is; Is it something
electrical or is it at a higher level, that OHCI and usb-device can't
"hear" each other anymore? (I know, I have to do a lot of reading, but I
am very curious about this one.)
Disconnects are triggered when the pull-up resistor on the D+ data line
(or D- line for low-speed devices) is removed. The controller sees
both lines go to a low-voltage state and interprets that as a
disconnection.
Thank you, that is very usefull, that way I can check with my scope if
that goes OK.
Yours sincerely,
Rene
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