On Sat, 2021-08-07 at 17:40 +0200, Andrew Lunn wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the > content is safe > > > I am not even clear what is the expected canonical behavior for a MAC > > driver. It parses rx-internal-delay-ps and tx-internal-delay-ps, and > > then what? > > So best practices are based around a MAC-PHY link. phy-mode is passed > to the PHY, and the MAC does not act upon it. MAC rx-internal-delay-ps > and tx-internal-delay-ps can be used to fine tune the link. You can > use them to add and sometimes subtract small amounts of delay. > > > It treats all "rgmii*" phy-mode strings identically? Or is it an > > error to have "rgmii-rxid" for phy-mode and non-zero > > rx-internal-delay-ps? > > I would say the first is correct, the second statement is false. You > should always be able to fine tune the link, independent of the PHY > mode. > > We also have to consider the case when the PHY is not actually able to > implement the delay. It hopefully returns -EOPNOTSUPP for anything > other than "rgmii". You can then put the full 2ns delay into > tx-internal-delay-ps nd rx-internal-delay-ps. I hope that using "*-internal-delay-ps" for Mac would be the right option. Shall i include these changes as we discussed in next revision of the patch?
