On Fri, 16 Nov 2001, Benny Sj�strand wrote: > > Yesterday i did some few modifications to the kernel trying to optimize > powerconsumption: > - Turning off sound stuff via EGPIO.
This should be done within the sound driver already. See drivers/sound/h3600-uda1341.c:h3600_audio_shutdown() which is called on the closing of the sound device and just before entering sleep mode through the pm callback in drivers/sound/sa1100-audio.c. > - Turning off IR port when it's not used. The same should happen inside drivers/net/irda/sa1100_ir.c. If it's not already implemented then that's the place where it should go. > - Setting the KADP EADP in sleep mode, NOTE: in the SA1110 manual it says > that this bit's can be set optionally enabled in sleep mode, but they > should be set self refresh bit is on. But if i enable > the KADP and EADP while it's running it hangs, i did not find out > why yet (my iPAQ is probably broken ...) > - Turn off OPT_NVRAM_ON and OPT_ON vi EGPIO > NOTE: none off those things above are currently done in kernel > when the iPAQ is set into sleep mode. Aren't those handled by the pcmcia core driver? If not that's probably the best place to do it. Also I noticed the pcmcia bus is enabled as soon as the pcmcia driver is initialized instead of turning it on only when a card insertion is detected, which is another source of power leak. > Then a question, are the EGPIO pins automatically set to "low" when the > iPAQ is to sleep mode, or do we need to take of this ? We probably need to do it explicitly. > Usually when i leave my office i set my iPAQ into sleep mode, when come > the next day on morning i turn it on and the battery level (returned from > /dev/misc/apm_bios) has gone down from 100% to ~ 25%. > > Today morning with the modification the battery level indication was ~ 78% > -;) and i hope that this sign that i am on the right way. This is great! P.S: my comments are based on the latest official ARM kernel source i.e. 2.4.15-pre4-rmk2. Nicolas _______________________________________________ http://lists.arm.linux.org.uk/mailman/listinfo/linux-arm Please visit the above address for information on this list.
