MFp4:

 - Add Command Completion Coalescing support.
 - Add SNTF support.
 - Add two more power management modes (4, 5), implemented on driver level.
 - Fix interface mode setting.
 - Reduce interface reset time.
 - Do not report meaningless protocol/transport versions.
 - Report CAP2 register content.
 - Some performance optimizations.

1 files changed, 16 insertions, 1 deletions

diff --git a/share/man/man4/ahci.4 b/share/man/man4/ahci.4
index 0173e1e..46660d3 100644
--- a/share/man/man4/ahci.4
+++ b/share/man/man4/ahci.4
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 26, 2009
+.Dd August 24, 2009
 .Dt AHCI 4
 .Os
 .Sh NAME
@@ -60,6 +60,13 @@ single MSI vector used, if supported (default);
 .It 2
 multiple MSI vectors used, if supported;
 .El
+.It Va hint.ahci.X.ccc
+controls Command Completion Coalescing (CCC) usage by the specified controller.
+Non-zero value enables CCC and defines maximum time (in ms), request can wait
+for interrupt, if there are some more requests present on controller queue.
+CCC reduces number of context switches on systems with many parallel requests,
+but it can decrease disk performance on some workloads due to additional
+command latency.
 .It Va hint.ahcich.X.pm_level
 controls SATA interface Power Management for specified channel,
 allowing some power to be saved at the cost of additional command
@@ -74,7 +81,15 @@ device is allowed to initiate PM state change, host is passive;
 host initiates PARTIAL PM state transition every time port becomes idle;
 .It 3
 host initiates SLUMBER PM state transition every time port becomes idle.
+.It 4
+driver initiates PARTIAL PM state transition 1ms after port becomes idle;
+.It 5
+driver initiates SLUMBER PM state transition 125ms after port becomes idle.
 .El
+Some controllers, such as ICH8, do not implement modes 2 and 3 with NCQ used.
+Because of artificial entering latency, performance degradation in modes
+4 and 5 is much smaller then in modes 2 and 3.
+.Pp
 Note that interface Power Management is not compatible with
 device presence detection.
 You will have to reset bus manually on device hot-plug.