On Wednesday 01 July 2009 01:01:00 Alan Stern wrote: > This looks like your problem. Low-speed devices are not allowed to > have bulk endpoints. Linux internally changes them to interrupt > endpoints with interval = 1 and maxpacket size no larger than 8. Maybe this device is a little "buggy". But Linux should support buggy devices as well. What about something like --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -387,6 +387,7 @@ static void acm_rx_tasklet(unsigned long struct acm_ru *rcv; unsigned long flags; unsigned char throttled; + struct usb_host_endpoint *ep; dbg("Entering acm_rx_tasklet"); @@ -462,11 +463,20 @@ urbs: rcv->buffer = buf; - usb_fill_bulk_urb(rcv->urb, acm->dev, - acm->rx_endpoint, - buf->base, - acm->readsize, - acm_read_bulk, rcv); + ep = (usb_pipein(acm->rx_endpoint) ? acm->dev->ep_in : acm->dev->ep_out) + [usb_pipeendpoint(acm->rx_endpoint)]; + if (usb_endpoint_xfer_int(&ep->desc)) + usb_fill_int_urb(rcv->urb, acm->dev, + acm->rx_endpoint, + buf->base, + acm->readsize, + acm_read_bulk, rcv, 0xff); + else + usb_fill_bulk_urb(rcv->urb, acm->dev, + acm->rx_endpoint, + buf->base, + acm->readsize, + acm_read_bulk, rcv); rcv->urb->transfer_dma = buf->dma; rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; @@ -1227,9 +1237,14 @@ made_compressed_probe: goto alloc_fail7; } - usb_fill_bulk_urb(snd->urb, usb_dev, - usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress), - NULL, acm->writesize, acm_write_bulk, snd); + if (usb_endpoint_xfer_int(epwrite)) + usb_fill_int_urb(snd->urb, usb_dev, + usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress), + NULL, acm->writesize, acm_write_bulk, snd, 0xff); + else + usb_fill_bulk_urb(snd->urb, usb_dev, + usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress), + NULL, acm->writesize, acm_write_bulk, snd); snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; snd->instance = acm; } It should work around devices like mine, but should not affect previously supported devices. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html