On Fri, Feb 14, 2025 at 10:47:39AM +0530, Swathi K S wrote: > > > > -----Original Message----- > > From: Andrew Lunn <andrew@xxxxxxx> > > Sent: 14 February 2025 05:50 > > To: Swathi K S <swathi.ks@xxxxxxxxxxx> > > Cc: krzk+dt@xxxxxxxxxx; andrew+netdev@xxxxxxx; davem@xxxxxxxxxxxxx; > > edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; > > robh@xxxxxxxxxx; conor+dt@xxxxxxxxxx; richardcochran@xxxxxxxxx; > > mcoquelin.stm32@xxxxxxxxx; alexandre.torgue@xxxxxxxxxxx; > > rmk+kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > > devicetree@xxxxxxxxxxxxxxx; linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH v6 1/2] dt-bindings: net: Add FSD EQoS device tree > > bindings > > > > > + phy-mode: > > > + enum: > > > + - rgmii-id > > > > phy-mode is normally a board property, in the .dts file, since the board > might > > decide to have extra long clock lines and so want 'rgmii'. > > > > The only reason i can think of putting rgmii-id here is if the MAC only > > supports 'rgmii-id', it is impossible to make it not add delays. > > If that is true, a comment would be good. > > > Hi Andrew, > Thanks for reviewing. > I think we already discussed this part some time back here [1] > [1] : > https://patchwork.kernel.org/project/linux-arm-kernel/patch/20230814112539.7 > 0453-2-sriranjani.p@xxxxxxxxxxx/#25879995 > Please do let me know if there is any other concern on this. We partially discussed this in this thread. As i said, what value you need here depends on the board design. The PCB could provide the 2ns delay, in which case, 'rgmii' would be the correct value to have in the board .dts file. Hence the binding should not restrict the value of phy-mode to just rgmii-id. All 4 rmgii values should be accepted. The only reason you would force only rgmii-id is if the MAC/PHY pair cannot do anything else. If that really is true, i would expect a comment in the binding, and the MAC driver to return -EINVAL for anything but rgmii-id. Andrew
