On Fri, 26 May 2006, yan seiner wrote: > I am trying to get usb 2 working on an OpenWrt access point. > > When I load up the the echi_hcd module and a webcam driver, everything > seems fine, but any attempt to use the webcam results in no response > from the USB system:
... > May 26 15:59:49 (none) kern.info kernel: hub.c: new USB device > 01:02.2-1, assigned address 2 > May 26 15:59:49 (none) kern.info kernel: hub.c: USB hub found > May 26 15:59:49 (none) kern.info kernel: hub.c: 4 ports detected > May 26 15:59:49 (none) kern.info kernel: hub.c: new USB device > 01:02.2-1.4, assigned address 3 > May 26 15:59:49 (none) kern.info kernel: drivers/usb/spca5xx.c: USB > SPCA5XX camera found. Logitech QC IM/Connect > May 26 15:59:49 (none) kern.info kernel: drivers/usb/spca5xx.c: > [spca5xx_probe:5480] Camera type JPEG > May 26 15:59:50 (none) kern.info kernel: drivers/usb/zc3xx.h: > [zc3xx_config:558] Find Sensor HV7131R(c) > May 26 15:59:50 (none) kern.info kernel: drivers/usb/spca5xx.c: > [spca5xx_getcapability:1765] maxw 640 maxh 480 minw 176 minh 144 > May 26 16:00:40 (none) kern.err kernel: drivers/usb/spca5xx.c: init > isoc: usb_submit_urb(0) ret -22 > May 26 16:00:40 (none) kern.info kernel: drivers/usb/spca5xx.c: > [spca5xx_open:2437] DEALLOC error on init_IsocMay 26 16:00:40 (none) > kern.warn kernel: > > I see the same behavior, but with a different error, using a different > webcam with a pwc v.10 driver, and usb_storage. I get isoc errors with > negative numbers. > > I have no idea what the negative errors mean. From googling about, I > found some mention of this being a problem but no real solutions.... > > Is there anything I can do to diagnose this, and eventually to fix this? The problem is that you are plugging a full-speed device (the camera) into a high-speed hub. The ehci-hcd driver currently isn't able to handle isochronous transfers in that situation very well. There are three ways to work around the problem. First, plug the camera directly into the computer instead of into the hub. Second, do "rmmod ehci-hcd" so that nothing runs at high speed. Third, use a full-speed (USB-1.1) hub, if you can find one, instead of the high-speed (USB-2.0) hub. Alan Stern ------------------------------------------------------- All the advantages of Linux Managed Hosting--Without the Cost and Risk! Fully trained technicians. The highest number of Red Hat certifications in the hosting industry. Fanatical Support. Click to learn more http://sel.as-us.falkag.net/sel?cmd=lnk&kid=107521&bid=248729&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
