On October 14, 2016 7:25:14 PM CEST, Andrew Lunn <and...@lunn.ch> wrote:
>> So after calling BMCR_PDOWN, the PHYSID1 and PHYSID2 registers are >> no longer readable. Is that expected? > >You are making two changes here. Is it the SGMII power down which is >causing the id registers to return 0xffff, or the BMCR_PDOWN. I would be curious to know about that as well. > >The generic suspend code sets the PDOWN bit, so it is assuming the PHY >will respond afterwards. After reading the spec again, it does not appear to me that a PHY with PDOWN set is guaranteed or even required to respond to other register reads such as MII_PHYID1/2, in which case we may have to implement a MDIO bus reset routine which clears PDOWN for all PHYs that we detect(ed), or as Andrew suggested, utilize the matching by compatible string with the PHY OUI in it. -- Florian
