At 05:19 PM 19/03/2006 +0100, you wrote:
Hi,
Raymond wrote:
Hi all!
P.S. As a side note, if I run "lsusb", I notice that if the camera is
picked up on bus 1, it fails and if it's picked up on bus 2 it succeeds
(this is all the same physical port on the computer). I'm guessing if the
first device plugged in (a hub or an "actual" device) is usb1.1 the
firmware assigns it to bus 2 otherwise it becomes bus 1 ... not sure if
that's a "normal" way of doing things or if it's something OQO have done ...
Yes that standard way of doing things :
the usb2 controller only manage high speed device. When a low/full speed
is detected it route the device to a "companion" controller which support
usb 1.
OK ... I sorta thought it'd be the one hub and the switching from 1.1 to
2.0 was handled in hardware (like on a hub) ... I guess that makes sense
too :-)
I suppose on our computer you have 2 drivers for usb controller : ehci for
usb2 and ohci/uhci for usb1. What happen if you unload/disable ehci driver ?
Unloading the ehci driver (rmmod ehci-hcd) gives the same result as if I
plugged in a USB1.1 hub first - it all works BUT I don't get USB2.0 speeds
which is a bit of a problem in my case unfortunately ...
For a laugh I tried disabling the ohci driver instead and everything fell
in a heap ...
Funnily enough, if I unload the ehci driver, plug in the USB2.0 hub then
the webcam, then reload the ehci driver (modprobe ehci-hcd) then run "xawtv
-c /dev/video0", I don't get any dmesg errors but I just get a black screen
and in the xawtv terminal I get "v4l2: oops: select timeout" then "v4l2:
read: Interrupted system call" then a backtrace ...
I had a quick, completely uninformed poke around the driver, it looks like
pwc-ctrl.c line 355, function set_video_mode_Kiara (which corresponds to
the camera I'm using), send_video_command is returning the -32 (broken
pipe) error which it's in turn getting from usb_control_msg ... does this
mean the source of the problem is pretty much beyond our control? I would
have thought usb_control_msg would be used by most (all?) USB drivers so
you'd expect them all to work or all to not work unless somehow there was
something weird about how the PWC chip responds to USB2.0 ...
- Raymond
P.S. I recognise Timon and Nala ... but who is Kiara?!
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