tree d74a1c1ca636c668226fb1fdec4b7f0fccd1c376
parent 3b08db37cb04a80dccac8c2d7b03690b5f179487
author Stefan Hajnoczi <stefanha@gmail.com> 1322036445 +0000
committer Greg Kroah-Hartman <gregkh@suse.de> 1322352852 -0800

staging: line6: alloc/free buffers in hw_params/hw_free

It is unsafe to free buffers in line6_pcm_stop(), which is not allowed
to sleep, since urbs cannot be killed completely there and only
unlinked.  This means I/O may still be in progress and the URB
completion function still gets invoked.  This may result in memory
corruption when buffer_in is freed but I/O is still pending.

Additionally, line6_pcm_start() is not supposed to sleep so it should
not use kmalloc(GFP_KERNEL).

These issues can be resolved by performing buffer allocation/freeing in
the .hw_params/.hw_free callbacks instead.  The ALSA documentation also
recommends doing buffer allocation/freeing in these callbacks.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>