On 08/29/2014 10:31 AM, Jason Gunthorpe wrote: > On Fri, Aug 29, 2014 at 08:35:36AM -0700, Sören Brinkmann wrote: > >> The compatible string is listed as optional property for PHYs. So, not >> having one is an option, I guess. But, I'd also prefer to at least keep >> the -c22 one, since I saw problems when I tried using -c45 (the Zed phy >> should support it...). > > -c45 and -c22 use a completely different MDIO protocol, Zed doesn't > have a 10GE port, so it certainly doesn't use -c45. Most recent 1GbE PHYs should also implement clause 45. It is a nice improvement if you are using lot of transactions, otherwise clause 45 over clause 22 is suitable and supported by the PHY library (for EEE in particular). > > If there is no compatible string at all the defined default is to use > -c22. Absolutely, the current binding makes that property optional, but I think we should make it mandatory instead. > >> Also, so far, we haven't had any phy nodes in our Zynq dts files and >> Ethernet worked, so the auto-detection there works pretty well >> apparently. But it may be problematic if more than a single PHY is on >> the MDIO bus, I'd assume. > > Phy autodetection has always worked in some cases, but for DT ethernet > bindings it is expected that there is an option to specify an explicit > MDIO bus, and a phy-handle phandle to point to the phy. The phy should > be explicitly called out with the fixed MDIO address specified to > avoid sketchy MDIO address auto probing. > > This provides the framework to specify interrupts and register > overrides for the phy in the DT. Absolutely, on the plus side, avoiding auto-detection also allows you to have a shorter boot time (usually by a factor of few hundreds of msecs depending on how the MDIO buses handle errors). -- Florian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
