[coreboot-gerrit] Patch merged into coreboot/master: pistachio: Use passive windowing as DQS gating scheme

[gerrit at coreboot.org]

the following patch was just integrated into master:
commit 1185c109e488c0706441527591376929809a24b2
Author: Ionela Voinescu <ionela.voinescu at imgtec.com>
Date:   Thu May 21 13:11:51 2015 +0100

    pistachio: Use passive windowing as DQS gating scheme
    
    Switching from active windowing DQS gating scheme to
    passive windowing mode resolves boot stability issues
    on chips found to have memory corruption issues during
    boot or memory tests.
    
    It was tested on Pistachio bring up board where DDR is
    initialized properly and ramstage executed correctly;
    We have cycled units over 12,000 times with no boot errors.
    
    This option was chosen over the alternative of using
    passive windowing mode for DQS training and after switching
    back to active mode, as this option was recommended by
    Synopsys. Using the alternative would give different
    timing values during training that were not longer accurate
    during normal activity.
    
    Change-Id: Ie604eddc0a9a982b2f89198f44deb88a01b7b322
    Signed-off-by: Ionela Voinescu <ionela.voinescu at imgtec.com>
    Reviewed-on: http://review.coreboot.org/10528
    Tested-by: build bot (Jenkins)
    Reviewed-by: Stefan Reinauer <stefan.reinauer at coreboot.org>


See http://review.coreboot.org/10528 for details.

-gerrit