Re: [PATCH v2] ARC: axs10x - add Ethernet PHY description in .dts

[Giuseppe CAVALLARO]

On 4/6/2016 11:12 AM, Vineet Gupta wrote:
> Hi,
>
> On Thursday 17 March 2016 03:11 PM, Alexey Brodkin wrote:
> > Following commit broke DW GMAC functionality on AXS10x boards:
> > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e34d65696d2ef13dc32f2a162556c86c461ed763
> >
> > That's what happens on eth0 up:
> > --------------------------->8------------------------
> > libphy: PHY stmmac-0:ffffffff not found
> > eth0: Could not attach to PHY
> > stmmac_open: Cannot attach to PHY (error: -19)
> > --------------------------->8------------------------
> >
> > Simplest solution is to add PHY description in board's .dts.
> > And so we do here.
> >
> > Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
> > Cc: Rob Herring <robh@xxxxxxxxxx>
> > Cc: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
> > Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: netdev@xxxxxxxxxxxxxxx
> > Cc: stable@xxxxxxxxxxxxxxx # 4.5.x
> > Cc: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
> > ---
> >
> > Changes v1 -> v2:
> >   * PHY node name changed to match real PHY number being used (Sergei)
> >
> >   arch/arc/boot/dts/axs10x_mb.dtsi | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi
> > index 44a578c..ab5d570 100644
> > --- a/arch/arc/boot/dts/axs10x_mb.dtsi
> > +++ b/arch/arc/boot/dts/axs10x_mb.dtsi
> > @@ -47,6 +47,14 @@
> >   			clocks = <&apbclk>;
> >   			clock-names = "stmmaceth";
> >   			max-speed = <100>;
> > +			mdio0 {
> > +				#address-cells = <1>;
> > +				#size-cells = <0>;
> > +				compatible = "snps,dwmac-mdio";
> > +				phy1: ethernet-phy@1 {
> > +					reg = <1>;
> > +				};
> > +			};
> >   		};
> >
> >   		ehci@0x40000 {
>
>
> So above DT fix for ARC went into 4.6-rc1 and ethernet was still broken on axs103
> board.
>
> ---------->8-------------
> libphy: PHY stmmac-0:ffffffff not found
> eth0: Could not attach to PHY
> stmmac_open: Cannot attach to PHY (error: -19)
> ---------->8-------------
>
> On 4.6-rc2 if I revert the DT change, ethernet works again.
>
> @Giuseppe, @Phil, @Gabriel, I see you have made changes in that area. I presume
> that above revert is the right/sufficient thing or do we need to do something else
> as well.

hmm I think so, we pushed all the changes in net-next to fix the MDIO
initialization according to the different DT parameter settings. So
unless there is some other case to cover, I think that the best
approach is to do the revert.

pls, let me know

peppe

> TIA,
> -Vineet