[alsa-devel] [PATCH 1/2] ALSA: core: add hooks for audio timestamps

[Pierre-Louis Bossart]

>> +				audio_frames = runtime->status->hw_ptr
>> +					+ runtime->delay;
>> +			audio_nsecs = audio_frames * 1000000000LL /
>> +				runtime->rate;
>
> This looks like a 64-bit division.
>
> And what happens if audio_frames becomes negative?

It's my understanding that hw_ptr represents the cumulative frames 
played since the beginning, not sure why it'd become negative, ever.
I know this deserves more love, I don't understand the notion of 
'boundary' and the use of the hw_ptr_base, I figured smarter people than 
me would help.
Thanks,
-Pierre