[coreboot-gerrit] Patch merged into coreboot/master: 37a1d6c AMD Hudson/Yangtze: Enable support for SATA port multipliers

the following patch was just integrated into master:
commit 37a1d6c9552b267c06c471cced5928d2385767e2
Author: Bruce Griffith 
Date:   Tue Jul 23 11:50:12 2013 -0600

AMD Hudson/Yangtze: Enable support for SATA port multipliers

This patch sets a bit in the Yangtze southbridge to enable
    the extra protocol necessary to handle port multiplier chips.
    This has been turned on during most of Kabini development
    without any notable impact. Olive Hill has an optional daughter
    board that incorporates Silicon Image Steel Vines chips.  This
    change has been tested with and without the daughter board.  This
    change can be regression tested using any Hudson-based motherboard,
    although it has no impact on boards with discreet Hudson/Bolton
    southbridges.

This was tested for impact on SATA performance in the absence of
    a port multiplier using the IOZone benchmarks within the Phoronix
    Test Suite.  A SATA 3 hard drive (6.0 Gbps) and an SSD were
    connected to the ports on Olive Hill without using the port
    multiplier card.  The test results contained more run-to-run
    variation within the same configuration than was seen in the
    aggregate results comparing the interface with and without the
    port multiplier protocol additions.  In other words, the test
    had less accuracy than the impact caused by turning on port
    multiplier support.

Change-Id: Ie87873b093f3e2a6a5c83b96ccb6c898d3e25f72
    Signed-off-by: Bruce Griffith 
    Reviewed-by: Martin Roth 
    Reviewed-by: Dave Frodin 
    Reviewed-on: http://review.coreboot.org/3808
    Tested-by: build bot (Jenkins)

See http://review.coreboot.org/3808 for details.

-gerrit