Hi Peter, On Thu, Sep 24, 2015 at 2:38 AM, Peter Chen <peter.c...@freescale.com> wrote: > On Wed, Sep 23, 2015 at 01:01:44PM +0100, Felipe F. Tonello wrote: >> req->actual == req->length means that there is no data left to enqueue, >> so free the request. >> >> Signed-off-by: Felipe F. Tonello <e...@felipetonello.com> >> --- >> >> Changes in v2: >> * Re enqueue not fully completed requests, instead of read ALSA buffers. >> >> drivers/usb/gadget/function/f_midi.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/usb/gadget/function/f_midi.c >> b/drivers/usb/gadget/function/f_midi.c >> index edb84ca..62356cf 100644 >> --- a/drivers/usb/gadget/function/f_midi.c >> +++ b/drivers/usb/gadget/function/f_midi.c >> @@ -256,10 +256,12 @@ f_midi_complete(struct usb_ep *ep, struct usb_request >> *req) >> /* We received stuff. req is queued again, below */ >> f_midi_handle_out_data(ep, req); >> } else if (ep == midi->in_ep) { >> - /* Our transmit completed. See if there's more to go. >> - * f_midi_transmit eats req, don't queue it again. */ >> - f_midi_transmit(midi, req); >> - return; >> + /* Our transmit completed. If there is no more to go, >> + don't queue it again. */ >> + if (req->actual == req->length) { >> + free_ep_req(ep, req); >> + return; >> + } > > I find f_midi_transmit will judge if there are more data, if without > data, it will free the request.
No. Transmit is called when ALSA trigger is called (whenever snd_*_read() snd_*_write() is called). The current code is not crashing anything, but I believe it is just wrong. It can cause potential problems in future if one is not careful when doing changes to it. I would like to send a v3 with free_ep_req(). Felipe > > Besides, does one trigger only do one transfer? Sorry, I can't make my > aplaymidi to receive data, probably due to hardware without midi > support? > > root@imx6qpsabreauto:~# aplaymidi > ALSA lib > /var/lib/jenkins/workspace/fido-3.14.28-X11-consolidated_new/temp_build_dir/build_all/tmp/work/cortexa9hf-vfp-neon-mx6qdl-poky-linux-gnueabi/alsa-lib/1.0.28-r0/alsa-lib-1.0.28/src/seq/seq_hw.c:457:(snd_seq_hw_open) > open /dev/snd/seq failed: No such file or directory > Cannot open sequencer - No such file or directory > > -- > > Best Regards, > Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/