pwc-webcam attached to usb-ohci card blocks on read() indefinitely.
Quoted 7 lines
The camera attached to the UHCI-controller running usb-uhci works just fine,out the three attached to the OHCI-controllers running usb-ohci don't. After a random amount of frames being read from a camera the read()-call blocks indefinitely until the device is closed. Next time the v4l-device is opened the program can again read frames from the camera but
read()always blocks after some time.
I can't help, but I have the exact same problem here. Closing the application (eg. camstream) and re-opening it makes it work again for a while.
As Carl-Johan said, this happens with or without the pwcx module, so that's not the problem.
I think it's an ohci problem.
Furthermore, the usb driver(s) behave strangely on connecting/disconnecting the camera. Sometimes this works flawlessly, sometimes I get a lot of USB timeout ("usb_control/bulk_msg: timeout") and/or "USBDEVFS_CONTROL failed dev x rqt 128 rq 6 len 490 ret -110" messages in the syslog. (Kernel is 2.4.16 and 2.4.18 - no difference) After a couple of times disconnecting and reconnecting the camera it's being detected. Since 2.4.18, the camera's LED sometimes is on, sometimes off - seems quite random.
Even closing the cam application (xawtv, camstream) after the camera stopped working never results in any error messages in the log, I only read "pwc: Closing video device: xxx frames received, dumped 0 frames, 0 frames with errors"
Thomas
Signature · 3 lines
Thomas Winischhofer Vienna/Austria mailto:[email protected] *** http://www.webit.com/tw
Quoted 5 lines · Thomas Winischhofer
Furthermore, the usb driver(s) behave strangely on connecting/disconnecting the camera. Sometimes this works flawlessly, sometimes I get a lot of USB timeout ("usb_control/bulk_msg: timeout") and/or "
USBDEVFS_CONTROLfailed dev x rqt 128 rq 6 len 490 ret -110" messages in the syslog. (Kernel is 2.4.16 and 2.4.18 - no difference)
Try removing /sbin/usbmodules (or renaming it) to see if this problem goes away. I have the same problem with some devices too, and am working on tracking it down.
thanks,
greg k-h
Just as a FYI, I had similar trouble using usb-uhci (440BX chipset) to a 680K using pwc/pwcx. I had to add a bunch of error recovery (close / open device, ignore open() failing and retry, etc).
I get a group of EMC messages logged , then the reset seems to take quite a while.
(2.4.19-pre2-ac2, but have seem this will many recent 2.4.x kernels)
Mark
Quoted 33 lines · Thomas Winischhofer
Quoted 6 lines
The camera attached to the UHCI-controller running usb-uhci works just fine,out the three attached to the OHCI-controllers running usb-ohci don't. After a random amount of frames being read from a camera the read()-call blocks indefinitely until the device is closed. Next time the v4l-device is opened the program can again read frames from the camera but
read()always blocks after some time.I can't help, but I have the exact same problem here. Closing the application (eg. camstream) and re-opening it makes it work again for a while.
As Carl-Johan said, this happens with or without the pwcx module, so that's not the problem.
I think it's an ohci problem.
Furthermore, the usb driver(s) behave strangely on connecting/disconnecting the camera. Sometimes this works flawlessly, sometimes I get a lot of USB timeout ("usb_control/bulk_msg: timeout") and/or "
USBDEVFS_CONTROLfailed dev x rqt 128 rq 6 len 490 ret -110" messages in the syslog. (Kernel is 2.4.16 and 2.4.18 - no difference) After a couple of times disconnecting and reconnecting the camera it's being detected. Since 2.4.18, the camera's LED sometimes is on, sometimes off - seems quite random.Even closing the cam application (xawtv, camstream) after the camera stopped working never results in any error messages in the log, I only read "pwc: Closing video device: xxx frames received, dumped 0 frames, 0 frames with errors"
Thomas
Signature · 5 lines
+-------------------------------------------------------------------------+ Mark Cooke The views expressed above are mine and are not Systems Programmer necessarily representative of university policy University Of Birmingham URL: http://www.sr.bham.ac.uk/~mpc/ +-------------------------------------------------------------------------+
Quoted 11 lines · Greg KH
Quoted 5 lines · Thomas Winischhofer
Furthermore, the usb driver(s) behave strangely on connecting/disconnecting the camera. Sometimes this works flawlessly, sometimes I get a lot of USB timeout ("usb_control/bulk_msg: timeout") and/or "
USBDEVFS_CONTROLfailed dev x rqt 128 rq 6 len 490 ret -110" messages in the syslog. (Kernel is 2.4.16 and 2.4.18 - no difference)Try removing
/sbin/usbmodules(or renaming it) to see if this problem goes away. I have the same problem with some devices too, and am working on tracking it down.
This actually made it, thanks so far! (usbmodules is located in /usr/sbin/ on my machine)
Of course, the main problem still exists. Additionally, the USB audio module is not loaded any more (for the built-in microphone of this camera).
Sorry if I ask something stupid, I am a total USB rookie - what's that /usr/sbin/usbmodules file for?
Thomas
Signature · 3 lines
Thomas Winischhofer Vienna/Austria mailto:[email protected] *** http://www.webit.com/tw
Quoted 3 lines · Thomas Winischhofer
Sorry if I ask something stupid, I am a total USB rookie - what's that
/usr/sbin/usbmodulesfile for?
The hotplug package uses it to try to determine some stuff about the device. Why it does this, I'm not really sure, it shouldn't be running for when a new device is plugged in, but only when the hotplug stuff is started the first time.
thanks,
greg k-h