[LAD] ALSA POLLIN event problems

Hey, I've been having a lot of trouble with ALSA and processing input in a full duplex loop, and I was wondering if anyone here had any insight. I'm using the ALSA poll file descriptor method with the mmap routines. Typically, my processing loop is blowing past the poll statement with input requests (POLLIN), causing the CPU usage to go off the charts as it's basically looping as fast as it can go. Now, I'm handling the inputs in a way that might not be correct. Often, ALSA is saying that the available frames is 1.5 times my buffer size (e.g., I set a 64 sample buffer and ALSA offers me 96 samples). I only get (begin/commit) input when the buffer size matches or exceeds the buffer length I send out to the card (the set buffer size), and if it exceeds that, I only pick up (commit) one buffer's length of frames. Is this wrong? If there is more input waiting, does ALSA immediately go and POLLIN again, or should I expect it to not bug me again until I've processed a POLLOUT event (the in and out are linked)? I'm not really sure how to handle this.. Cheers, Louis