Hi, On 08/25/2014 07:43 PM, Jassi Brar wrote: > On Mon, Aug 25, 2014 at 10:52 PM, Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: >> I believe you want to do the following in afunc_set_alt(). >> - req->length = prm->max_psize; >> + req->length = uac2->c_pktsize; >> > Sorry I intended... > - prm->max_psize = hs_epin_desc.wMaxPacketSize; > + prm->max_psize = agdev->uac2.c_pktsize; Yes, that would be another way, but as we might have sample rates and formats that can be configured at runtime, I opted for another variable and leave max_psize = wMaxPacketSize. That should work equally well but it's more flexible in the future, right? > Also USB-IN is capture for host, but in f_uac2 it is playback. So you > may want to do > > - rate = opts->c_srate * opts->c_ssize * num_channels(opts->c_chmask); > - rate = opts->p_srate * opts->p_ssize * num_channels(opts->p_chmask); Ah, right. Will also fix in v3. > BTW, why not do the same for USB-OUT as well? it shouldn't hurt. Not sure if I'm following, but on the OUT side (capture on the gadget), the model is entirely different. We don't have to estimate the packet sizes, and we're not really interested whether the data rate matches our system clock. The host will start sending in whatever it believes to be the correct rate. With other sound interfaces, it will normally be notified on a regular base if it should speed up or slow down. But as we don't have a feedback endpoint in f_uac2, the host will keep sending at its original data rate, and we have to sink away whatever we get, and feed it to the virtual ALSA device. As I've described in my previous mail, this is intended for audio streaming. The virtual capture interface on the gadget will be in sync with the host's clock, not with its own system clock. If we wanted to change that, we'd need to implement a feedback endpoint, but I don't currently see any need for that. I'll fix the two things you pointed out, and resend v3. Probably tomorrow. Best regards, and thanks for your feedback, Daniel -- 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
