[RESEND PATCH net-next v4 0/3] Enable 2.5Gbps speed for stmmac

Vladimir Oltean olteanv at gmail.com
Thu Jun 3 06:47:52 PDT 2021


On Thu, Jun 03, 2021 at 01:43:09PM +0000, Sit, Michael Wei Hong wrote:
> Vladimir,
> 
> > -----Original Message-----
> > From: Vladimir Oltean <olteanv at gmail.com>
> > Sent: Thursday, June 3, 2021 9:28 PM
> > To: Russell King (Oracle) <linux at armlinux.org.uk>
> > Cc: Sit, Michael Wei Hong <michael.wei.hong.sit at intel.com>;
> > Jose.Abreu at synopsys.com; andrew at lunn.ch;
> > hkallweit1 at gmail.com; kuba at kernel.org;
> > netdev at vger.kernel.org; peppe.cavallaro at st.com;
> > alexandre.torgue at foss.st.com; davem at davemloft.net;
> > mcoquelin.stm32 at gmail.com; Voon, Weifeng
> > <weifeng.voon at intel.com>; Ong, Boon Leong
> > <boon.leong.ong at intel.com>; Tan, Tee Min
> > <tee.min.tan at intel.com>; vee.khee.wong at linux.intel.com;
> > Wong, Vee Khee <vee.khee.wong at intel.com>; linux-stm32 at st-
> > md-mailman.stormreply.com; linux-arm-
> > kernel at lists.infradead.org; linux-kernel at vger.kernel.org
> > Subject: Re: [RESEND PATCH net-next v4 0/3] Enable 2.5Gbps
> > speed for stmmac
> > 
> > Michael,
> > 
> > On Thu, Jun 03, 2021 at 02:08:51PM +0100, Russell King (Oracle)
> > wrote:
> > > Hi,
> > >
> > > On Thu, Jun 03, 2021 at 07:50:29PM +0800, Michael Sit Wei Hong
> > wrote:
> > > > Intel mGbE supports 2.5Gbps link speed by overclocking the
> > clock
> > > > rate by 2.5 times to support 2.5Gbps link speed. In this mode,
> > the
> > > > serdes/PHY operates at a serial baud rate of 3.125 Gbps and
> > the PCS
> > > > data path and GMII interface of the MAC operate at 312.5
> > MHz instead of 125 MHz.
> > > > This is configured in the BIOS during boot up. The kernel
> > driver is
> > > > not able access to modify the clock rate for 1Gbps/2.5G mode
> > on the
> > > > fly. The way to determine the current 1G/2.5G mode is by
> > reading a
> > > > dedicated adhoc register through mdio bus.
> > >
> > > How does this interact with Vladimir's "Convert xpcs to
> > phylink_pcs_ops"
> > > series? Is there an inter-dependency between these, or a
> > preferred
> > > order that they should be applied?
> > >
> > > Thanks.
> > 
> > My preferred order would be for my series to go in first, if
> > possible, because I don't have hardware readily available to test,
> > and VK already has tested my patches a few times until they
> > reached a stable state.
> > 
> > I went through your patches and I think rebasing on top of my
> > phylink_pcs_ops conversion should be easy.
> > 
> > Thanks.
> Sure! I am okay to let you merge your codes and rebase my changes later on
> Do let me know when I can start rebasing and send in the next revision

Well, you are already copied to my patches, so you should get the
notification email at the same time as I would.
https://patchwork.kernel.org/project/netdevbpf/cover/20210602162019.2201925-1-olteanv@gmail.com/



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