On Wed, Aug 27, 2014 at 12:20 PM, Daniel Mack <daniel@xxxxxxxxxx> wrote:
> On 08/27/2014 06:08 AM, Jassi Brar wrote:
>> On Wed, Aug 27, 2014 at 3:23 AM, Daniel Mack <zonque@xxxxxxxxx> wrote:
>
>>> + uac2->p_interval = (1 << (ep_desc->bInterval - 1)) * factor;
>>> + req_len = rate / uac2->p_interval;
>>>
>> + if (opts->p_srate % uac2->p_interval)
>> + req_len += fsz;
>> .....
>>
>>> + uac2->p_residue = 0;
>>> } else {
>>> dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
>>> return -EINVAL;
>>> @@ -1128,7 +1188,7 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
>>>
>>> req->zero = 0;
>>> req->context = &prm->ureq[i];
>>> - req->length = prm->max_psize;
>>> + req->length = req_len;
>>> req->complete = agdev_iso_complete;
>>> req->buf = prm->rbuf + i * req->length;
>>>
>> .... otherwise req[0]->buf might overlap req[1]->buf's first frame
>> for when we need to send an extra frame.
>
> Hmm? The first USB_XFERS packets will only contain zeros, and we're only
> preparing those here. For every successive packet, the length is
> recalculated and the audio material is copied in accordingly before the
> requets is requeued. What buffers should overlap here?
>
For 44100/2/S16, req_len is 176 or 44 frames. But we need to send 45
frames in a packet occasionally.
req[0]->buf = rbuf + 0 and req[1]->buf = rbuf + 176.
But what if we req[0] needed to carry the packet with 45 frames?
-jassi
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