MFC 261000,261785,263238,263322,264302:
Various AHCI fixes:
- Fix issue with stale fields from a recycled request pulled off the
freelist.
- Provide an indication a "PIO Setup Device to Host FIS" occurred while
executing the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands.
- Provide an indication a "D2H Register FIS" occurred during a SET FEATURES
command.
- Though there currently isn't a way to insert new media into an ATAPI
drive, at least pretend to support Asynchronous Notification (AN) to
avoid a guest needlessly polling for it.
- Don't reissue in-flight commands.
- Constrain the amount of data returned to what is actually available
not the size of the buffer.
git-svn-id: svn://svn.freebsd.org/base/stable/10@267339
ccf9f872-aa2e-dd11-9fc8-
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