>>>>> "Alan" == Alan Stern <[EMAIL PROTECTED]> writes:
Alan> On 19 Dec 2007, Russell Senior wrote: >> I have an application on an embedded device. It was all happily >> working with a usb-storage device, a pl2303-based gps device and a >> usb-audio device plugged into a usb2 hub. Now I've added a usb >> mouse and when I open the associated /dev/event0, I start seeing >> the messages below when I try to play audio to the usb-audio >> device. >> >> cannot submit datapipe for urb 0, error -28: not enough bandwidth >> output: ioctl(SNDCTL_DSP_SYNC): Broken pipe cannot submit datapipe >> for urb 0, error -28: not enough bandwidth cannot submit datapipe >> for urb 0, error -28: not enough bandwidth output: >> ioctl(SNDCTL_DSP_SYNC): Broken pipe cannot submit datapipe for urb >> 0, error -28: not enough bandwidth >> >> [...] >> >> With gpsd running (opening /dev/ttyUSB0), with "cat < /dev/event0 > >> /dev/null", then "/usr/bin/madplay -Q -a -10 --no-tty-control >> random.mp3" seems to screw me. Without the /dev/event0 open, I >> don't have the problem. >> >> Am I screwed, or is there something I can tweak? Alan> You can try replacing your hub. Some USB 2.0 hubs have greater Alan> bandwidth capacity for full-speed devices than yours (they have Alan> separate Transaction Translators for each port). Can you suggest one? I have a few lying around to try, but if I have to buy one I'd like to get the right one the first time. Alan> Or you can try plugging some of those full-speed devices Alan> directly into the computer rather than into the hub. Regrettably, the board has but one usb port. Alan> The storage device doesn't matter, but the gps, audio, and mouse Alan> devices are all sharing the hub's bandwidth. Right. Thanks! -- Russell Senior ``I have nine fingers; you have ten.'' [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
