K 10
svn:author
V 3
mav
K 8
svn:date
V 27
2014-09-06T19:43:48.430819Z
K 7
svn:log
V 272
Save one register read (AHCI_IS) for AHCI controllers with only one port.

For controllers with only one port (like PCIe or M.2 SSDs) interrupt can
come from only one source, and skipping read saves few percents of CPU time.

MFC after:	1 month
H/W donated by:	I/O Switch

END