sidcomp.audio test failure

[Ben Elliston <bje at redhat dot com>]

I tracked down a failure in the `linusraw.exp' test today.  It's an
interesting one!  The problem is that the audio component uses
non-blocking I/O to write the audio data to /dev/audio.  On my older
Linux system with a cs4232 sound chipset, the test passes.  On my
newer system with a cs46xx chipset, the driver has a maximum write
size limitation of 32kb.

I have confirmed all of this by reading the drivers/sound/audio.c
source from the kernel.

Basically, I think this test is bogus.  It is a mistake to not
consider the possibility that the driver will return with any possible
value for the number of bytes written.  Instead, the test should
perhaps keep polling the component until it has emptied its buffer and
*then* check that the tx-sample-count is the correct value.  Thoughts?

In the meantime, I have marked the test as XFAIL.  It might fail, it
might not -- that depends on your OS and your sound hardware.  ;-(

Ben