the following patch was just integrated into master: commit 152e5a03a130cea3009685cbf7eb0ea354d9fd1c Author: Aaron Durbin adurbin@chromium.org Date: Wed Feb 10 11:01:49 2016 -0600
libpayload: honor TSC information under CONFIG_LP_TIMER_RDTSC
When CONFIG_LP_TIMER_RDTSC is enabled honor the TSC information exported in the coreboot tables as the cpu_khz frequency. That allows get_cpu_speed() not to be called which currently relies on the 8254 PIT. As certain x86 platforms allow that device to be optional or turned off for power saving reasons, allow a path where get_cpu_speed() is no longer called. Additionally, this approach also allows the libpayload to not duplicate logic that already exists in coreboot.
BUG=chrome-os-partner:50214 BRANCH=glados TEST=Confirmed in payload TSC frequency is honored instead of using get_cpu_speed().
Change-Id: Ib8993afdfb49065d43de705d6dbbdb9174b6f2c4 Signed-off-by: Aaron Durbin adurbin@chromium.org Reviewed-on: https://review.coreboot.org/13671 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth martinroth@google.com Reviewed-by: Andrey Petrov andrey.petrov@intel.com
See https://review.coreboot.org/13671 for details.
-gerrit