[coreboot] Patch merged into coreboot/master: 538ad1f CPU: Set flex ratio to nominal TDP ratio in bootblock

gerrit at coreboot.org gerrit at coreboot.org
Tue Jul 24 23:49:47 CEST 2012

the following patch was just integrated into master:
commit 538ad1f6c7fcba133931d2d2673c0bf50b5f9aad
Author: Duncan Laurie <dlaurie at chromium.org>
Date:   Mon Jul 9 09:58:35 2012 -0700

    CPU: Set flex ratio to nominal TDP ratio in bootblock
    CPUs with configurable TDP will run the TSC at the max non-turbo
    ratio for the maximum TDP value, which can cause issues if another
    TDP is desired.  To deal with this we set the flex ratio to the
    nominal TDP ratio early in the boot and then configure the Soft
    Reset Data registers so the PCH can tell the CPU what frequency
    to run at after a reset.
    This is done very early in the bootblock because it is necessary
    to reset the system after setting a flex ratio.
    The end result is that the TSC will now increment at the max
    non-turbo frequency for the nominal TDP.
    On some system with 1.8GHz CPU ensure that the kernel
    detects the CPU speed as ~1800mhz rather than ~2300mhz:
    > dmesg | grep "MHz processor"
    [    0.004000] Detected 1795.801 MHz processor.
    Change-Id: I8436dced9199003b6423186a2b041e3f7b84ab8c
    Signed-off-by: Duncan Laurie <dlaurie at google.com>

Build-Tested: build bot (Jenkins) at Tue Jul 24 23:10:06 2012, giving +1
Reviewed-By: Ronald G. Minnich <rminnich at gmail.com> at Tue Jul 24 23:49:46 2012, giving +2
See http://review.coreboot.org/1329 for details.


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