Hello, I’ve recently noticed a problem with Modecom Venus and A4Tech PK-333E webcams. Both can be put into a “bad state” in which they refuse to do anything until they’re reconnected to the usb port. The test case is simple: gst-launch-1.0 v4l2src ! videoconvert ! autovideosink Setting pipeline to PAUSED ... Pipeline is live and does not need PREROLL ... Setting pipeline to PLAYING ... New clock: GstSystemClock eKilled gst-launch-1.0 v4l2src ! videoconvert ! autovideosink Setting pipeline to PAUSED ... Pipeline is live and does not need PREROLL ... Setting pipeline to PLAYING ... New clock: GstSystemClock ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could not read from resource. Additional debug info: gstv4l2bufferpool.c(994): gst_v4l2_buffer_pool_poll (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: poll error 1: Invalid argument (22) Execution ended after 0:00:00.046823946 Setting pipeline to PAUSED ... Setting pipeline to READY ... Setting pipeline to NULL ... Freeing pipeline ... The GStreamer process has to be killed with the -9: kill -9 `pidof gst-launch-1.0` The dmesg log shows this: [88000.804362] usb 3-3: new high-speed USB device number 4 using xhci_hcd [88000.864107] usb 3-3: New USB device found, idVendor=0ac8, idProduct=3460 [88000.864113] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [88000.864116] usb 3-3: Product: Venus USB2.0 Camera [88000.864118] usb 3-3: Manufacturer: Vimicro Corp. [88000.865088] uvcvideo: Found UVC 1.00 device Venus USB2.0 Camera (0ac8:3460) [88000.866783] input: Venus USB2.0 Camera as /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/input/input16 [88024.007404] uvcvideo: Failed to query (GET_DEF) UVC control 2 on unit 2: -110 (exp. 2). [88024.307041] uvcvideo: Failed to query (GET_DEF) UVC control 2 on unit 2: -110 (exp. 2). [88025.837884] uvcvideo: Failed to set UVC probe control : -32 (exp. 26). [88030.830854] uvcvideo: Failed to set UVC probe control : -110 (exp. 26). [88035.824615] uvcvideo: Failed to set UVC probe control : -110 (exp. 26). [88040.818399] uvcvideo: Failed to set UVC probe control : -110 (exp. 26). [88045.812171] uvcvideo: Failed to set UVC probe control : -110 (exp. 26). [88050.805941] uvcvideo: Failed to set UVC probe control : -110 (exp. 26). [88088.249967] xhci_hcd 0000:00:14.0: Signal while waiting for configure endpoint command [88088.250000] usb 3-3: Not enough bandwidth for altsetting 0 [88090.907927] xhci_hcd 0000:00:14.0: ERROR Transfer event for disabled endpoint or incorrect stream ring [88090.907940] xhci_hcd 0000:00:14.0: @0000000115c5f460 00000000 00000000 0c000000 03058000 [88091.021791] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88006b0fa540 [88091.021797] xhci_hcd 0000:00:14.0: Trying to add endpoint 0x82 without dropping it. [88091.021802] usb 3-3: Not enough bandwidth for altsetting 7 [88091.021805] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88006b0fa540 -- Best regards, Krzysztof Borowczyk -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
