soc/intel/cannonlake: Disable Legacy PME for Root ports

Legacy PME are enabled by default in FSP-S UPD. This policy sets
PME Interrupt Enable (PIE) bit of RCTL register to trigger interrupt
generation when RSTS.PS state has changed (either due to 0->1 transition
or due to this bit being set with RSTS.PS already set). Due to this
interrupt generation, system wakes from sleep immediately it enters.

This patch overrides root port legacy pme upd policy from coreboot to
ensure no false SCI is triggerd when system is in S3/S0ix state.

BUG=b:113083354
BRANCH=none
TEST=Able to make S3 resume using wake on wifi connect/disconnect usecase
without any failure.

Change-Id: I779fac711eeeed65ea379fad1cc400052d8a00eb
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/28947
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

0 files changed, 0 insertions, 0 deletions