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author | Zhuo-hao Lee <zhuo-hao.lee@intel.com> | 2017-03-14 10:27:28 +0800 |
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committer | Aaron Durbin <adurbin@chromium.org> | 2017-03-17 03:36:09 +0100 |
commit | 07f60aa56fefa0aeb4f896d63267a54ddfae0715 (patch) | |
tree | 4ea54d893074df433f7c5f24e75fdd4abf30c930 /src/mainboard/lenovo/t520/smihandler.c | |
parent | 6f80ccc357702f87baf43440d97a49bcce999393 (diff) |
soc/intel/apollolake: Reduce D3 cold delay for eMMC controller
eMMC Controller is taking over 100ms to resume during runtime which
results in I/O latency issues on the Apollo Lake system such as Snappy.
The cause is the Linux Kernel setting the firmware reset time to
100 ms by default.
This patch adds _DSM method for eMMC comtroller for specifying the
device readiness durations. Function index 9 returns package of five
integers to set D3 cold delay to zero and ACPI constant Ones for the
elements where overriding the default values is not desired.
BUG=b:35774937
BRANCH=none
TEST=update snappy coreboot and test i/o latency is under 100ms
Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@intel.com>
Signed-off-by: Sowmya V <v.sowmya@intel.com>
Change-Id: Idcfe4252b20bead15c2e5b9cb000ff797295f06a
Reviewed-on: https://review.coreboot.org/18806
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Diffstat (limited to 'src/mainboard/lenovo/t520/smihandler.c')
0 files changed, 0 insertions, 0 deletions