On Tue, Jan 26, 2016 at 1:55 PM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > On Mon, Jan 25, 2016 at 09:55:58PM -0800, Andrey Smirnov wrote: >> Add commands for low-level access to MDIO bus. > > Do we really need this? We can already read/write phy registers using > /dev/phyx which imo is quite convenient since it can be accessed with > regular md/mw commands. > > This of course is currently limited to the phys that are actually > registered, you can't just bang on MDIO addresses on which no phys are > registered. Maybe we could register all phys on a MDIO bus instead of > only the used ones? Just to explain the purpose of this patch -- there are number of reasons we might want to be able to access "unregistered" PHYs: - Not all MDIO attached devices would have PHYSID1,2 registers available which might cause mdiobus_scan() to not detect those PHYs - MDIO bus troubleshooting As for registering all PHYs on a bus, correct me if I am wrong but that would result in 32*N number of entries in /dev, where N is number of MDIO buses in the system. The device I am working with right now has 3 MDIO buses which would mean that I'd end up with 96 additional entries in /dev, which might be a little bit overwhelming from UI point of view. The other UI problem with that approach is that /dev/phy's are numbered linearly so in order to figure out how to access device on bus N at address M, user would have to perform N*32 + M in their head. Andrey _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
