On 31.01.2024 06:23, Viresh Kumar wrote: > On 30-01-24, 18:46, Manivannan Sadhasivam wrote: >> Agree. But what I'm saying is, right now there is no DT property in the >> interconnect consumer nodes to specificy the bw requirements. This is all >> hardcoded in the respective ICC consumer drivers. > > I thought there are a lot of users already in there.. > > $ git grep -i opp.*bps arch/arm64/boot/dts/ | wc -l > 864 > >> But when we use OPP to control bw, the bw requirements come from DT. This is >> what I see as a difference. Because, only nodes making use of OPP will specify >> bw in DT and other nodes making use of just ICC will not. >> >> Maybe I'm worrying too much about these details... But it looks like >> inconsistency to me. > > Right. So is there inconsistency right now ? Yes, there is. > > The important question we need to answer is where do we want to see > all these drivers (specially new ones) in the future. What's the right > thing to do eventually ? Hardcode stuff ? Or Move it to DT ? > > The answer is DT for me, so the code can be generic enough to be > reused. This is just one step in the right direction I guess. > Eventually the drivers must get simplified, which they are I guess. I'm lukewarm on this. A *lot* of hardware has more complex requirements than "x MBps at y MHz", especially when performance counters come into the picture for dynamic bw management. OPP tables can't really handle this properly. Konrad
