Add the AAC_DEBUG option to enable debugging in the aac driver.
Correct a race condition in the interrupt handler where the
controller may queue a fib to a response queue after the driver
has serviced the queue but before the interrupt is cleared.
This could leave a completed fib stranded in the response queue
unless another I/O completed and generated another interrupt.
Reviewed by: msmith
with the driver locking up under load.
- Restructure so that we use a static pool of commands/FIBs, rather than
allocating them in clusters. The cluster allocation just made things
more complicated, and allowed us to waste more memory in peak load
situations.
- Make queueing macros more like my other drivers. This adds queue stats
for free. Add some debugging to take advantage of this.
- Reimplement the periodic timeout scan. Kick the interrupt handler
and the start routine every scan as well, just to be safe. Track busy
commands properly.
- Bring resource cleanup into line with resource allocation. We should
now clean up correctly after a failed probe/unload/etc.
- Try to start new commands when old ones are completed. We weren't doing
this before, which could lead to deadlock when the controller was full.
- Don't try to build a new command if we have found a deferred command.
This could cause us to lose the deferred command.
- Use diskerr() to report I/O errors.
- Don't bail if the AdapterInfo structure is the wrong size. Some variation
seems to be normal. We need to improve our handing of 2.x firmware sets.
- Improve some comments in an attempt to try to make things clearer.
- Restructure to avoid some warnings.
