[alsa-devel] [PATCH v5 1/2] amidi: add delay option

[Felipe Ferreri Tonello]

Hi Clemens,

On 23/08/16 11:37, Clemens Ladisch wrote:
> Felipe Ferreri Tonello wrote:
>> On 22/08/16 13:43, Clemens Ladisch wrote:
>>> Felipe F. Tonello wrote:
>>>> +				if (data > send_data)
>>>> +					usleep(delay * 1000);
>>>
>>> The MIDI data is sent asynchonously, so this delay is not _between_ messages.
>>> You'd have to add 320 µs for any byte not yet sent (I guess you have to use
>>> snd_rawmidi_status_get_avail() to find out how many have been sent).
>>
>> Right. Or I can just use snd_rawmidi_drain()?
> 
> This function not only drains the ALSA buffer, but also waits for the
> hardware FIFO to empty.  And most drivers do not implement this, in
> which case the framework just does a fixed wait of 50 ms, which would
> correspond to a FIFO size of 156 bytes.
> 

Ok, so does that mean that it is not safe to use drain()? If that is the
case, than I will use snd_rawmidi_status_get_avail().

-- 
Felipe
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0x92698E6A.asc
Type: application/pgp-keys
Size: 7195 bytes
Desc: not available
URL: <http://mailman.alsa-project.org/pipermail/alsa-devel/attachments/20160823/f0c3da27/attachment.bin>