Audio capture too, or just playback?

Would this patch also help diagnose latency in the case of audio capture, 
not just playback?

Because they seem to be related but different problems; playback latency 
is the time between a userspace process making a syscall to write audio 
and the kernel poking the audio hardware, capture latency the time between 
the audio hardware asserting an interrupt and the userspace process 
receiving the data. Or at least thats my educated guess, I Am Not A Kernel 
Hacker.