Overflow in calculating audio timestamp

[Alan Young]

sound/core/pcm_lib.c:update_audio_tstamp() contains the following 
calculation:

         audio_nsecs = div_u64(audio_frames * 1000000000LL,
                 runtime->rate);

This will result in a 64-bit overflow after 4.4 days at 48000 Hz, or 1.1 
days at 192000.

Are you interested in a patch to improve this?

The same calculation occurs in a couple of other places.

Alan.