On Tue, Oct 12, 2010 at 5:53 PM, Nicolas Pitre <nico@xxxxxxxxxxx> wrote: >> > Yes, but in this case the suspend methods are inappropriate when the >> > phone is in live usage. They are meant to be used, say, when the phone >> > becomes unused and its flap is folded. Otherwise, what is supposed to >> > happen when you actually want the SDIO card to be suspended if the >> > suspend method is cut out? >> >> "Flap is folded"... It is not the case for usual smartphones anymore. :) >> Simple scenario - you are siting in chat, wait like 15 sec and your >> screen goes Off, after another 5 sec kernel gets suspend command and >> tries to suspend. And you are getting new message - you want to resume >> quickly and process this packet with no delay. > > OK... and how do you want to achieve that? > > Why isn't MMC_PM_KEEP_POWER suitable for this? It just allows to keep power for SDC controller. It doesn't change suspend/resume behavior from SDIO device perspective. > >> Maybe what I am describing seems weird, but phone developers are >> fighting for every mA. > > How can you save power when the WIFI interface is not in use if you > disabled the suspend method with your patch? You see, we are not talking about wlan chip power. CPU is consuming in average more energy, so we are talking about overall savings or consumption and not specifically wlan. I mean, definitely turn off SDC controller and remove device will save power, BUT we will spend much more time on resume meaning - more power for CPU... > >> And mmc card resume if usually deferred - to reduce tiem and save >> power, but this is a different issue. > > How much time are we talking about? The best thing is to defer resume till it will be needed. > > Nicolas > Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
