Hi Rob/Mark, Do you have any more comments, please? Thanks, Tai On Mon, May 2, 2016 at 2:46 PM, Tai Tri Nguyen <ttnguyen@xxxxxxx> wrote: > Hi Rob, > > On Mon, May 2, 2016 at 1:56 PM, Rob Herring <robh@xxxxxxxxxx> wrote: >> On Wed, Apr 20, 2016 at 12:31:22PM +0100, Will Deacon wrote: >>> On Mon, Apr 18, 2016 at 01:04:53PM -0700, Tai Tri Nguyen wrote: >>> > >> +Required properties for MCB subnode: >>> > >> +- compatible : Shall be "apm,xgene-pmu-mcb". >>> > >> +- reg : First resource shall be the MCB PMU resource. >>> > >> +- index : Instance number of the MCB PMU. >>> > >> + >>> > >> +Required properties for MC subnode: >>> > >> +- compatible : Shall be "apm,xgene-pmu-mc". >>> > >> +- reg : First resource shall be the MC PMU resource. >>> > >> +- index : Instance number of the MC PMU. >>> > > >>> > > Don't use indexes. You probably need phandles to the nodes these are >>> > > related to. >>> > > >>> > > How many variations of child nodes do you expect to have? 2, 10, 50? You >>> > > might want to just collapse all this down to a single node and put this >>> > > information in the driver if it is fixed for each SoC and there's only a >>> > > handful. >>> > > >>> > >>> > For each kind of PMU, for example memory controller PMU, I expect to >>> > have the number of instances up to 8. >>> > They are actually all independent PMU nodes and have their own CSR memory bases. >>> > The indexes are used for exposing the devices to perf user only. It >>> > doesn't have an impact on the programming model. >>> > Mark also had the same concern. >>> >>> Regardless, I'll need an ack from Rob or Mark before I can merge this. >> >> I still have a concern with this. Needing an index to expose to the user >> is generally not a valid reason. That's OS specific and therefore >> doesn't belong in DT. >> >> Rob > > I can use device name here. However, the perf event names will be > different between DT and ACPI which I want to avoid. > And the names don't look good at all. > Also, specifically for MC and MCB PMUs, the indexes are compared > against the active MC/MCB mask to find out whether they are populated > or not. > Without using the index property, I will also need a mapping function > of physical device addresses and their physical ids. > > Thanks, > -- > Tai -- Tai -- 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
