On Thu, Apr 08, 2021 at 07:36:37PM +0200, Uwe Kleine-König wrote: > On Thu, Apr 08, 2021 at 05:51:36PM +0200, Clemens Gruber wrote: > > On Thu, Apr 08, 2021 at 02:50:40PM +0200, Thierry Reding wrote: > > > Yes, I think that's basically what this is saying. I think we're perhaps > > > getting hung up on the terminology here. PWM_STAGGERING_ALLOWED gives > > > the impression that we're dealing with some provider-specific feature, > > > whereas what we really want to express is that the PWM doesn't care > > > exactly when the active cycle starts and based on that a provider that > > > can support it may optimize the EMI behavior. > > > > > > Maybe we can find a better name for this? Ultimately what this means is > > > that the consumer is primarily interested in the power output of the PWM > > > rather than the exact shape of the signal. So perhaps something like > > > PWM_USAGE_POWER would be more appropriate. > > > > Yes, although it would then no longer be obvious that this feature leads > > to improved EMI behavior, as long as we mention that in the docs, I > > think it's a good idea > > > > Maybe document it as follows? > > PWM_USAGE_POWER - Allow the driver to delay the start of the cycle > > for EMI improvements, as long as the power output stays the same > > I don't like both names, because for someone who is only halfway into > PWM stuff it is not understandable. Maybe ALLOW_PHASE_SHIFT? Sounds good to me. > When a consumer is only interested in the power output than > > .period = 20 > .duty_cycle = 5 > > would also be an allowed response for the request > > .period = 200 > .duty_cycle = 50 > > and this is not what is in the focus here. Right. If Thierry agrees, I can spin up a new revision. Maybe we can get it into 5.13 after all. Thanks, Clemens
