On Tue, Jun 27, 2017 at 04:11:21PM +0800, Chen-Yu Tsai wrote: > On Tue, Jun 27, 2017 at 4:05 PM, Corentin Labbe > <clabbe.montjoie@xxxxxxxxx> wrote: > > On Mon, Jun 26, 2017 at 01:18:23AM +0100, André Przywara wrote: > >> On 31/05/17 08:18, Corentin Labbe wrote: > >> > The dwmac-sun8i is a heavy hacked version of stmmac hardware by > >> > allwinner. > >> > In fact the only common part is the descriptor management and the first > >> > register function. > >> > >> Hi, > >> > >> I know I am a bit late with this, but while adapting the U-Boot driver > >> to the new binding I was wondering about the internal PHY detection: > >> > >> > >> So here you seem to deduce the usage of the internal PHY by the PHY > >> interface specified in the DT (MII = internal, RGMII = external). > >> I think I raised this question before, but isn't it perfectly legal for > >> a board to use MII with an external PHY even on those SoCs that feature > >> an internal PHY? > >> On the first glance that does not make too much sense, but apart from > >> not being the correct binding to describe all of the SoCs features I see > >> two scenarios: > >> 1) A board vendor might choose to not use the internal PHY because it > >> has bugs, lacks features (configurability) or has other issues. For > >> instance I have heard reports that the internal PHY makes the SoC go > >> rather hot, possibly limiting the CPU frequency. By using an external > >> MII PHY (which are still cheaper than RGMII PHYs) this can be avoided. > >> 2) A PHY does not necessarily need to be directly connected to > >> magnetics. Indeed quite some boards use (RG)MII to connect to a switch > >> IC or some other network circuitry, for instance fibre connectors. > >> > >> So I was wondering if we would need an explicit: > >> allwinner,use-internal-phy; > >> boolean DT property to signal the usage of the internal PHY? > >> Alternatively we could go with the negative version: > >> allwinner,disable-internal-phy; > >> > >> Or what about introducing a new "allwinner,internal-mii-phy" compatible > >> string for the *PHY* node and use that? > >> > >> I just want to avoid that we introduce a binding that causes us > >> headaches later. I think we can still fix this with a followup patch > >> before the driver and its binding hit a release kernel. > >> > >> Cheers, > >> Andre. > >> > > > > I just see some patch, where "phy-mode = internal" is valid. > > I will try to find a way to use it > > Can you provide a link? https://lkml.org/lkml/2017/6/23/479 > > I'm not a fan of using phy-mode for this. There's no guarantee what > mode the internal PHY uses. That's what phy-mode is for. For each soc the internal PHY mode is know and setted in emac_variant/internal_phy So its not a problem. Patch comming soon -- 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
