On Thu, Feb 25, 2021 at 02:18:35PM +0200, Vladimir Oltean wrote: > From: Vladimir Oltean <vladimir.olt...@nxp.com> > > The ENETC port 0 MAC supports in-band status signaling coming from a PHY > when operating in RGMII mode, and this feature is enabled by default. > > It has been reported that RGMII is broken in fixed-link, and that is not > surprising considering the fact that no PHY is attached to the MAC in > that case, but a switch. > > This brings us to the topic of the patch: the enetc driver should have > not enabled the optional in-band status signaling for RGMII unconditionally, > but should have forced the speed and duplex to what was resolved by > phylink. > > Note that phylink does not accept the RGMII modes as valid for in-band > signaling, and these operate a bit differently than 1000base-x and SGMII > (notably there is no clause 37 state machine so no ACK required from the > MAC, instead the PHY sends extra code words on RXD[3:0] whenever it is > not transmitting something else, so it should be safe to leave a PHY > with this option unconditionally enabled even if we ignore it). The spec > talks about this here: > https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/138/RGMIIv1_5F00_3.pdf > > Fixes: 71b77a7a27a3 ("enetc: Migrate to PHYLINK and PCS_LYNX") > Cc: Florian Fainelli <f.faine...@gmail.com> > Cc: Andrew Lunn <and...@lunn.ch> > Cc: Russell King <rmk+ker...@armlinux.org.uk>
Looks better, thanks. Acked-by: Russell King <rmk+ker...@armlinux.org.uk> > Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com> > --- > Changes in v2: > - Don't write to the MAC if speed and duplex did not change. > - Don't update the speed with the MAC enabled. > - Remove the logic for enabling in-band signaling in enetc_mac_config. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
