Re: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT
From: Stephen Boyd <hidden>
Date: 2015-06-19 18:44:03
Also in:
linux-arm-kernel, linux-devicetree
On 06/18, Viresh Kumar wrote:
On 17-06-15, 18:30, Stephen Boyd wrote:quoted
An operating-point(s?)-names property seems ok... but doesn't that mean that every CPU that uses the OPP has to have the same list of operating-point-names?Why do you think so? For me the operating-points-v2-names property will be present in CPU node (as there is no OPP node which can have it) and so every CPU is free to choose what it wants to.
Yes.
quoted
It would make sense to me if the operating points were called something different depending on *which* CPU is using them, but in this case the only name for the operating point is "slow" or "fast", etc.I am completely confused now. :)
As am I.
The problem you stated now was there with the current state of bindings. The name is embedded into the OPP table node and so is fixed for all the CPUs. Moving it to the CPU node will give all CPUs a chance to name it whatever they want to. And the same list has to be replicated to all CPUs sharing the clock rails.
Yes I don't see how the name will be different for any CPU, hence my complaint/question about duplicate names in each CPU. I guess it isn't any worse than clock-names though so I'm fine with it.
quoted
In reality we've assigned them names like speedX-binY-vZ so that we know which speed bin, voltage bin, and version they're part of. Maybe OPP node properties like qcom,speed-bin = <u32>, qcom,pvs-bin = <u32>, etc. would be better?Lets see, only if we can't get the generic stuff for this.quoted
At the least, operating-points-names will be required on qcom platforms. A fixed ordering known to the platform would mean that we know exactly how many voltage bins and speed bins and how many voltage bins per speed bin are used for a particular SoC, which we've avoided knowing so far.What are we referring to fixed ordering? If we have both a list of phandles to OPP tables and a list of names, they can be rearranged in whatever fashion we want. Isn't it?
This is a reply to Rob's question about fixed ordering without a names property. That's unlikely to work out for qcom chips. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in