The urb_dequeue() method "forgets" to unlink 'struct musb_qh' from the control/ bulk schedule list when an URB being cancelled is the only one queued to its endpoint, which will cause musb_advance_schedule() to "block" once it reaches 'struct musb_qh' with now empty URB list, and so URBs queued for other control/ bulk endpoints after the one being dequeued will not be served. Hence add code to unlink and free 'struct musb_qh' if its URB list emptied to this method and remove now useless check from musb_advance_schedule().
The only exception case is when we're called from the driver's callback -- musb_giveback() doesn't expect us to pull out 'qh' from under it (it'll kill this qh later anyway) and we want to keep around a qh with is_ready flag clear because some drivers like usbaudio.c do submit a new URB after cancelling all pending ones which leads to URB being started when it shouldn't be and started all over again after the control returns to musb_giveback()... Signed-off-by: Sergei Shtylyov <[email protected]> --- The patch is against the recent Linus' kernel... drivers/usb/musb/musb_host.c | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-) Index: linux-2.6/drivers/usb/musb/musb_host.c =================================================================== --- linux-2.6.orig/drivers/usb/musb/musb_host.c +++ linux-2.6/drivers/usb/musb/musb_host.c @@ -431,7 +431,7 @@ musb_advance_schedule(struct musb *musb, else qh = musb_giveback(qh, urb, urb->status); - if (qh && qh->is_ready && !list_empty(&qh->hep->urb_list)) { + if (qh != NULL && qh->is_ready) { DBG(4, "... next ep%d %cX urb %p\n", hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh)); @@ -2071,7 +2071,19 @@ static int musb_urb_dequeue(struct usb_h ret = 0; qh->is_ready = 0; __musb_giveback(musb, urb, 0); - qh->is_ready = ready; + + /* + * If the URB list has emptied, it's time to kill this qh. + * However, if this was called from the driver callback, + * we don't really want to do it now, deferring it until + * we return to musb_giveback(), or bad things will happen... + */ + if (ready && list_empty(&qh->hep->urb_list)) { + qh->hep->hcpriv = NULL; + list_del(&qh->ring); + kfree(qh); + } else + qh->is_ready = ready; } else ret = musb_cleanup_urb(urb, qh, urb->pipe & USB_DIR_IN); done: _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
