> -----Original Message----- > From: Russell King - ARM Linux admin <li...@armlinux.org.uk> > Sent: 03 August 2020 12:07 > To: Madalin Bucur (OSS) <madalin.bu...@oss.nxp.com> > Cc: Andrew Lunn <and...@lunn.ch>; Vikas Singh > <vikas.si...@puresoftware.com>; f.faine...@gmail.com; hkallwe...@gmail.com; > netdev@vger.kernel.org; Calvin Johnson (OSS) <calvin.john...@oss.nxp.com>; > kuldip dwivedi <kuldip.dwiv...@puresoftware.com>; Vikas Singh > <vikas.si...@nxp.com> > Subject: Re: [PATCH 2/2] net: phy: Associate device node with fixed PHY > > On Mon, Aug 03, 2020 at 08:33:19AM +0000, Madalin Bucur (OSS) wrote: > > > -----Original Message----- > > > From: netdev-ow...@vger.kernel.org <netdev-ow...@vger.kernel.org> On > > > Behalf Of Andrew Lunn > > > Sent: 01 August 2020 18:11 > > > To: Russell King - ARM Linux admin <li...@armlinux.org.uk> > > > Cc: Vikas Singh <vikas.si...@puresoftware.com>; f.faine...@gmail.com; > > > hkallwe...@gmail.com; netdev@vger.kernel.org; Calvin Johnson (OSS) > > > <calvin.john...@oss.nxp.com>; kuldip dwivedi > > > <kuldip.dwiv...@puresoftware.com>; Madalin Bucur (OSS) > > > <madalin.bu...@oss.nxp.com>; Vikas Singh <vikas.si...@nxp.com> > > > Subject: Re: [PATCH 2/2] net: phy: Associate device node with fixed > PHY > > > > > > On Sat, Aug 01, 2020 at 10:41:32AM +0100, Russell King - ARM Linux > admin > > > wrote: > > > > On Sat, Aug 01, 2020 at 09:52:52AM +0530, Vikas Singh wrote: > > > > > Hi Andrew, > > > > > > > > > > Please refer to the "fman" node under > > > > > linux/arch/arm64/boot/dts/freescale/fsl-ls1046a-rdb.dts > > > > > I have two 10G ethernet interfaces out of which one is of fixed- > link. > > > > > > > > Please do not top post. > > > > > > > > How does XGMII (which is a 10G only interface) work at 1G speed? Is > > > > what is in DT itself a hack because fixed-phy doesn't support 10G > > > > modes? > > > > > > My gut feeling is there is some hack going on here, which is why i'm > > > being persistent at trying to understand what is actually going on > > > here. > > > > Hi Andrew, > > > > That platform used 1G fixed link there since there was no support for > > 10G fixed link at the time. PHYlib could have tolerated 10G speed there > > With a one-liner. > > That statement is false. It is not a "one liner". fixed-phy exposes > the settings to userspace as a Clause 22 PHY register set, and the > Clause 22 register set does not support 10G. So, a "one liner" would > just be yet another hack. Adding Clause 45 PHY emulation support > would be a huge task. > > > I understand that PHYLink is working to describe this > > Better, but it was not there at that time. Adding the dependency on > > PHYLink was not desirable as most of the users for the DPAA 1 platforms > > were targeting kernels before the PHYLink introduction (and last I've > > looked, it's still under development, with unstable APIs so we'll > > take a look at this later, when it settles). > > I think you need to read Documentation/process/stable-api-nonsense.rst > particularly the section "Stable Kernel Source Interfaces". > > phylink is going to be under development for quite some time to come > as requirements evolve. For example, when support for QSFP interfaces > is eventually worked out, I suspect there will need to be some further > changes to the driver interface. This is completely normal. > > Now, as to the stability of the phylink API to drivers, it has in fact > been very stable - it has only changed over the course of this year to > support split PCS, a necessary step for DPAA2 and a few others. It has > been around in mainline for two years, and has been around much longer > than that, and during that time it has been in mainline, the MAC facing > interface has not changed until recently. > > So, I find your claim to be quite unreasonable. > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
I see you agree that there were and there will be many changes for a while, It's not a complaint, I know hot it works, it's just a decision based on required effort vs features offered vs user requirements. Lately it's been time consuming to try to fix things in this area. Regards Madalin
