Hi, On Thu, 2020-09-17 at 15:54 +0200, Hans de Goede wrote: > Hi, > > On 9/17/20 3:50 PM, Benjamin Berg wrote: > > On Thu, 2020-09-17 at 14:51 +0200, Hans de Goede wrote: > > > > Compared to the WIP lenovo-dytc "perfmode" driver, we're missing > > > > something to advertise the unavailability of a profile, and the reason > > > > for that unavailability. > > > > > > UGh, do we really need to export this though. We have the lap_mode thing > > > already; and that is something which we will need for other reasons in > > > the future too. Any UI for selecting performance modes can display a > > > warning when lap_mode is true saying that: "The laptop has detected that it > > > is sitting on someone's lap and that performance may be limited > > > because of this." (feel free to improve the text). > > > > Well, for dytc_perfmode there are actually always the three states > > L/M/H. It just happens that the kernel will write "H*" (was "M*" until > > yesterday) when the performance mode is degraded due to lap detection. > > > > Think of dytc_perfmode as a profile that sets a number of things: > > * Thermal Limits > > * Fan Behaviour > > * possibly more > > > > While dytc_lapmode will only enforce a change to the thermal limit. > > So "performance" (H) is technically a valid mode even when the lap is > > detected. > > > > > I guess we could split the "value" attribute from my reply to Benjamin's > > > email into "configured_value" (rw) and "actual_value" (rw) attributes. > > > If we have the info we might as well export it I guess,. > > > > I consider the "*" purely a curtsey to users that read the attribute > > directly using e.g. cat to help with the interpretation. It probably is > > not interesting to userspace applications/daemons. > > So if there is a difference between M and H and H* then I think we should > just do the KISS thing and only have a single value attribute and in the > new interface handle the H* like H (p-p-d can still check the lap_mode > attribute to differentiate the 2 if it wants to). I guess you are saying to drop "H*" and only have "L"/"M"/"H"? If so, fine with me, but we probably need that input in reply to https://patchwork.kernel.org/patch/11730133/#23618881 then :) In principle it could be useful for userspace to know that performance is or would be dramatically impacted. i.e. when dytc_lapmode is 1, then you might want to say something like: performance states >= 75 are impacted due to "lapmode" But, not sure if a kernel interface for that is useful or whether we should just put that kind of knowledge into userspace. Benjamin
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