On 7 December 2011 10:57, Serghei Amelian <serghei@thel.ro> wrote:
Hello,
I need some opinions about features provided by Power Management System.
So far I implemented a battery monitor and backlight control. Now, I want to
debate about:
1) Governors. KPowersave come with governor controller, but a guy from #udev
irc channel adviced me that is actually is not necessary to implement it in a
gui interface, because actually we don't want to change governors but we need
to burn less energy.
Check this "good practices" guide:
http://www.codon.org.uk/~mjg59/power/good_practices.html
Again, a power manager needs to manage the power. There are probably situtations where people want to use powersave or use performance, either way the power manager should allow me to adjust my CPU state.
2) DPMS and screensavers. In my opinion, DPMS control should be passed to
screensaver, not to be controlled by power manager.
Why? I think that Power Manager should react only to events related to power
supplies (like AC adapter plugged in, AC unplugged, battery low, etc) or ACPI
events like "lid closed", "power button pressed", etc.
Right and these things need to load different profiles which are preset.
Shutting down the monitor when the user is away from keyboard is not exactly
related to power management, seem natural to be a part of screensaver.
Opinions? Ideas?
I think you have the wrong idea. "power management" refers to managing the power usage and controls things that change this. DPMS (aka power display for monitors) should belong here. Laptop Screens and Monitors both pull an enormous amount of power and it is up to the power manager to utilize this appropriately. Not to mention the power manager is required to set different profiles to control my screen settings.
if the screensaver had to do this, then the screen saver would end up reimplementing the profiles and make it an enormous PITA.
the reason HAL was great is because it allowed me to manage all of my power needs from a single library. I don't understand why this was bad. As long as the library or application is well written, there is no reason we shouldn't implement all the things we need. that means we need DPMS and CPU freq settings and backlight and more. why? because they are all power related functions.
Calvin Morrison