On Mon, Jun 23, 2014 at 10:59 AM, Pawel Moll <pawel.moll@xxxxxxx> wrote: > On Mon, 2014-06-23 at 16:43 +0100, Rob Herring wrote: >> On Mon, Jun 23, 2014 at 9:13 AM, Pawel Moll <pawel.moll@xxxxxxx> wrote: >> > On Fri, 2014-06-20 at 18:09 +0100, Mark Rutland wrote: >> >> > +- max-memory-bandwidth: maximum bandwidth in bytes per second that the >> >> > + cell's memory interface can handle >> >> >> >> When should I set this, given it is optional? >> > >> > When there is a (significant) limitation of the bandwidth available for >> > the cell's memory interface. One will either be told by the soc guys or >> > will figure it out in the hard way, as we did :-( >> >> What are you going to do with this information? b/w is a function of >> screen size and pixel depth. Are you going to refuse certain configs >> based on that? Seems like someone doing their own modes should know >> what they are doing and the limitations. >> >> Again, drop it until there is a defined need for this. > > Yes, there is. Use case: PL111 is wired up to a HDMI formatter, which > will take everything up to 1080p. This is what a DRM driver (what/if > it's ready) will get from the encoder driver (and rightly so). But the > chip interconnect limitations is make the chip being able to get 480p at > 60Hz tops. > > Or do you want me to add a subnode with timings for all achievable modes > instead? I want this solved in a generic way and not something pl111 specific. If this is already defined then use it. If not, I would drop this for now and get a pl111 binding in place finally. Rob -- 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
