firewire: ohci: lazy bus time initialization
authorClemens Ladisch <clemens@ladisch.de>
Thu, 24 May 2012 17:29:19 +0000 (19:29 +0200)
committerStefan Richter <stefanr@s5r6.in-berlin.de>
Sun, 27 May 2012 10:31:11 +0000 (12:31 +0200)
commit9d60ef2bd87f201c509cfae13ba6c9013446673d
tree76c4c28d674d33c924f638cde404bfafede88e15
parentf07d42ac7f2a7d650125d0cd7a79631c4522edaf
firewire: ohci: lazy bus time initialization

The Bus_Time CSR is virtually never used, so we can avoid burning CPU in
interrupt context for 1 or 3 IsochronousCycleTimer accesses every minute
by not tracking the bus time until the CSR is actually accessed for the
first time.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
drivers/firewire/ohci.c