On 13 July 2017 at 11:25, Jisheng Zhang <jszhang@xxxxxxxxxxx> wrote: > Hi Ulf, > > On Thu, 13 Jul 2017 11:18:32 +0200 Ulf Hansson wrote: > >> On 13 July 2017 at 00:16, Zhoujie Wu <zjwu@xxxxxxxxxxx> wrote: >> > From: Hu Ziji <huziji@xxxxxxxxxxx> >> > >> > Add Xenon specific system-level suspend and resume support. >> > Especially during resume, re-configure Xenon specific registers >> > since registers setting will be lost in suspend if Xenon is power off. >> >> I recommend to start with deploying runtime PM support instead of >> system PM support. Then on top of such change, you should make use of >> the runtime PM centric path to get system sleep support for "free" >> (and thus all the nice benefits). > > I'm not sure whether runtime PM is useful for xenon case. The xenon HW > support ACG(Auto Clock Gating) and SDCLK-Off-While-Idle features, that's > to say we even don't need to do anything but achieve the runtime PM gains. Yeah, but that's only internally managed by mmc controller. The clock will not be unprepared/disabled, from clock tree point of view. Isn't that also worth doing? Kind regards Uffe > > Thanks, > Jisheng > >> >> Please have a look at sdhci-of-at91 for a good reference. >> Regarding sdhci-of-at91, there is currently a patch [1], which adds >> dealing with restoring context of registers after a system resume. >> Similar to what you need. >> >> Kind regards >> Uffe >> >> [1] >> https://patchwork.kernel.org/patch/9837951/ >> >> [...] >> >> Kind regards >> Uffe > -- 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
