> On Sun, Sep 20, 2020 at 02:39:39AM +0200, ansuelsmth@xxxxxxxxx > wrote: > > > > > > > -----Messaggio originale----- > > > Da: Andrew Lunn <andrew@xxxxxxx> > > > Inviato: domenica 20 settembre 2020 02:31 > > > A: Ansuel Smith <ansuelsmth@xxxxxxxxx> > > > Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>; Richard Weinberger > > > <richard@xxxxxx>; Vignesh Raghavendra <vigneshr@xxxxxx>; Rob > Herring > > > <robh+dt@xxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>; Jakub > > > Kicinski <kuba@xxxxxxxxxx>; Heiner Kallweit <hkallweit1@xxxxxxxxx>; > > > Russell King <linux@xxxxxxxxxxxxxxx>; Frank Rowand > > > <frowand.list@xxxxxxxxx>; Boris Brezillon <bbrezillon@xxxxxxxxxx>; > linux- > > > mtd@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux- > > > kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx > > > Oggetto: Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac- > > > address-increment > > > > > > > + mac-address-increment: > > > > + description: > > > > + The MAC address can optionally be increased (or decreased using > > > > + negative values) from the original value readed (from a nvmem > > cell > > > > > > Read is irregular, there is no readed, just read. > > > > > > > + for example). This can be used if the mac is readed from a > > dedicated > > > > + partition and must be increased based on the number of device > > > > + present in the system. > > > > > > You should probably add there is no underflow/overflow to other bytes > > > of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > > > > > > > + minimum: -255 > > > > + maximum: 255 > > > > + > > > > + mac-address-increment-byte: > > > > + description: > > > > + If 'mac-address-increment' is defined, this will tell what byte > > of > > > > + the mac-address will be increased. If 'mac-address-increment' is > > > > + not defined, this option will do nothing. > > > > + default: 5 > > > > + minimum: 0 > > > > + maximum: 5 > > > > > > Is there a real need for this? A value of 0 seems like a bad idea, > > > since a unicast address could easily become a multicast address, which > > > is not valid for an interface address. It also does not seem like a > > > good idea to allow the OUI to be changed. So i think only bytes 3-5 > > > should be allowed, but even then, i don't think this is needed, unless > > > you do have a clear use case. > > > > > > Andrew > > > > Honestly the mac-address-increment-byte is added to give user some > control > > but I > > don't really have a use case for it. Should I limit it to 3 or just remove > > the function? > > If you have no use case, just remove it and document that last byte > will be incremented. I somebody does need it, it can be added in a > backwards compatible way. > > Andrew I just rechecked mac-address-increment-byte and we have one device that use it and would benefits from this. I will change the Documentation to min 3 and leave it.
