tree bc27bbc90f5379c894cd9b797458dcf42e325d09
parent 0a7d99c089eea04ec03958f96dd180bffa6fcc4a
author Angel Pons <th3fanbus@gmail.com> 1610410884 +0100
committer Patrick Georgi <pgeorgi@google.com> 1610709881 +0000

nb/intel/sandybridge: Clarify command timing calculation

Command timing is the absolute value of the most negative `pi_coding`
value across all ranks, or zero if there are no negative values. Use the
MAX() macro to ease proving that `cmd_delay` can never be negative, and
then drop the always-false underflow check.

The variable type for `cmd_delay` still needs to be signed because of
the comparisons with `pi_coding`, which is a signed value. Using an
unsigned type would result in undefined and also undesired behavior.

Change-Id: I714d3cf57d0f62376a1107af63bcd761f952bc3a
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49320
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>