Hi Elia, Mark, et al. Elia, Mark I'm mailing you both because both of you have pdx86 patches pending to add a vendor specific sysfs-attribute for selecting performance-profiles for resp. HP and Lenovo Thinkpad laptops. I think that this shows that we might need to start thinking about a generic kernel API for this, otherwise we will end up with slight different options per vendor ... So it seems we may need something like: /sys/class/system_performance_profile Where we would then get e.g.: /sys/class/system_performance_profile/thinkpad_acpi/performance_profile And then we need to standardize on the names/values which performance_profile can show / accept when written too. The big question is what do we do if there are more then 3 profiles? One option would be something like the following: cat /sys/class/system_performance_profile/thinkpad_acpi/performance_profile low-power [balanced] performance cat /sys/class/system_performance_profile/thinkpad_acpi/extra_performance_profiles extra-low-power balanced-performance-mix So we add an optional extra_performance_profiles sysfs attribute and we ask all drivers implemeting this class to implement at least the 3 standard profiles (by mapping 3 of their options to these) and optional they can offer extra profiles (with free form names) in the extra_performance_profiles sysfs attribute under the class-device. The idea behind putting the extra profiles in a separate sysfs-attribute is that reading the main performance_profile attribute will always show one selected, even if one of the extra profiles is actually in use, then the driver should also show the closest standardized profile as being active. This will allow userspace code to always rely on the standard interface both for getting a representation of the currently active profile as well as for setting the active profile. Elia, Mark, I assume that both of you want to get your patches for this upstream sooner, rather then later. But I think we should put them on hold until we have an agreement on a shared userspace API for this. I would like to think that the above proposal is a good start, if we can quickly (*) decide on an userspace API here Regards, Hans p.s. I guess we should also add an optional lap_mode sysfs attribute to the class-device, to have all the info for the Thinkpads in one place. *) but not too quickly, it is important we get this right
