Rex-BC Chen <rex-bc.chen@xxxxxxxxxxxx> writes: > On Thu, 2022-04-14 at 14:48 -0700, Kevin Hilman wrote: [...] >> >> You explained this well, but it's still not an appropriate solution >> IMO, >> because you're still not setting the target that is requested by the >> CPUfreq core. >> >> The job of ->set_target() is to set the frequency *requested by >> CPUfreq >> core*. If you cannot do that, you should return failure. What you >> posted >> in the original patch and what you're proposing here is to ignore the >> frequency passed to ->set_target() and do something else. In the >> orignal patch, you propose do to nothing. Now, you're ignoring the >> target passed in and setting something else. In both cases, the >> CPUfreq >> core things you have successfuly set the frequency requested, but you >> have not. This means there's a mismatch between what the CPUfreq >> core & >> governer things the frequency is and what is actually set. *This* is >> the part that I think is wrong. >> >> Instead, the proper way of restricting available frequencies is to >> use >> governors or policies. This ensures that the core & governors are >> aligned with what the platform driver actually does. >> >> As I proposed earlier, I think a clean solution to this problem is to >> create a temporary policy at probe time that restricts the available >> OPPs based on what the current CCI freq/voltage are. Once CCI driver >> is >> loaded and working, this policy can be removed. >> >> Kevin >> >> > > Hello Kevin, > > In new proposal, we DO set the cpufreq passed by cpufreq core. > We just not set the corresponding voltage of target frequency which > is lookedup from opp table. OK, this makes more sense. I thought you were ignoring frequency change also. [...] > In summary, we think it's a proper solution to cover the situation > when cci is not probed. Yes, this is OK with me. > I think there is something to improve: > We can choose to lookup cci opp table using cci freq to determine > the voltage instead of voltage_on_boot. > But IMO, it's not neccessary to register cci opp table inside cpufreq > driver just for the short period. I agree. > Because I finish to prepare other patches and I think we also can > take a look at other patches which are including some cleanup, I will > send next version today. > If there is any concern and question, we can discuss in next version. OK, I'll have a closer look at the new version. Kevin
