Messages in this thread |  | | Subject | Re: [PATCH net] Revert "net: stmmac: platform: Fix MDIO init for platforms without PHY" | From | Robin Murphy <> | Date | Tue, 7 Jan 2020 10:56:18 +0000 |
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On 07/01/2020 5:46 am, Sriram Dash wrote: >> From: Florian Fainelli <f.fainelli@gmail.com> >> Subject: [PATCH net] Revert "net: stmmac: platform: Fix MDIO init for > platforms >> without PHY" >> >> This reverts commit d3e014ec7d5ebe9644b5486bc530b91e62bbf624 ("net: >> stmmac: platform: Fix MDIO init for platforms without PHY") because it > breaks >> existing systems with stmmac which do not have a MDIO bus sub-node nor a >> 'phy-handle' property declared in their Device Tree. On those systems, the >> stmmac MDIO bus is expected to be created and then scanned by >> of_mdiobus_register() to create PHY devices. >> >> While these systems should arguably make use of a more accurate Device > Tree >> reprensentation with the use of the MDIO bus sub-node an appropriate 'phy- >> handle', we cannot break them, therefore restore the behavior prior to the > said >> commit. >> >> Fixes: d3e014ec7d5e ("net: stmmac: platform: Fix MDIO init for platforms >> without PHY") >> Reported-by: Heiko Stuebner <heiko@sntech.de> >> Reported-by: kernelci.org bot <bot@kernelci.org> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> > Nacked-by: Sriram Dash <Sriram.dash@samsung.com> > >> --- >> Heiko, >> >> I did not add the Tested-by because the patch is a little bit different > from what >> you tested, even if you most likely were not hitting the other part that I > was >> changing. Thanks! >> >> drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >> b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >> index cc8d7e7bf9ac..bedaff0c13bd 100644 >> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c >> @@ -320,7 +320,7 @@ static int stmmac_mtl_setup(struct platform_device >> *pdev, static int stmmac_dt_phy(struct plat_stmmacenet_data *plat, >> struct device_node *np, struct device *dev) { >> - bool mdio = false; >> + bool mdio = true; > > > This is breaking for the platforms with fixed-link. > stih418-b2199.dts and 169445.dts to name a few. > > For the newer platforms, they should provide the mdio/ snps,dwmac-mdio > property in the device tree as we are checking the mdio/ snps,dwmac-mdio > property in the stmmac_platform driver for the mdio bus memory allocation. > For existing platforms, I agree we should not break them, but we should make > the code correct. And make the existing platforms adapt to the proper code. > There is a proposed solution. > https://lkml.org/lkml/2020/1/7/14 > > What do you think?
The binding says that the phy handle and mdio child node are optional, so "update all of the DTBs!" is not a viable solution. I'm far from an expert here, but AFAICS the fault of the current code is that it assumes the lack of a phy handle implies a fixed link, so the obvious answer is to actually check whether the "fixed-link" property is present.
Robin.
> >> static const struct of_device_id need_mdio_ids[] = { >> { .compatible = "snps,dwc-qos-ethernet-4.10" }, >> {}, >> -- >> 2.19.1 > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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