On 04/10/2021 at 21:15, Sean Anderson wrote:
While we're on the subject, could someone clarify the relationship
between the various speed capabilities? What's the difference between
MACB_CAPS_GIGABIT_MODE_AVAILABLE, MACB_CAPS_HIGH_SPEED, MACB_CAPS_PCS,
and macb_is_gem()? Would there ever be a GEM without GIGABIT_MODE?
Yes. GEM is a new revision of the IP that is capable of doing Gigabit
mode or not. sama7g5_emac_config is typically one of those doing only
10/100.
HIGH_SPEED without PCS? Why doesn't SGMII care if we're a gem (I think
this one is a bug, because it cares later on)?
MACB_CAPS_HIGH_SPEED and MACB_CAPS_PCS were added by
e4e143e26ce8f5f57c60a994bdc63d0ddce3a823 ("net: macb: add support for
high speed interface"). In this commit it is said that "This
controller has separate MAC's and PCS'es for low and high speed
paths." Maybe it's a hint.