On Fri, Mar 31, 2017 at 10:58:16PM -0400, Rob Clark wrote: > On Fri, Mar 31, 2017 at 1:54 PM, Will Deacon <will.deacon@xxxxxxx> wrote: > > On Thu, Mar 09, 2017 at 09:05:43PM +0530, Sricharan R wrote: > >> This series provides the support for turning on the arm-smmu's > >> clocks/power domains using runtime pm. This is done using the > >> recently introduced device links patches, which lets the symmu's > >> runtime to follow the master's runtime pm, so the smmu remains > >> powered only when the masters use it. > > > > Do you have any numbers for the power savings you achieve with this? > > How often do we actually manage to stop the SMMU clocks on an SoC with > > a handful of masters? > > > > In other words, is this too coarse-grained to be useful, or is it common > > that all the devices upstream of the SMMU are suspended? > > well, if you think about a phone/tablet with a command mode panel, > pretty much all devices will be suspended most of the time ;-) Well, that's really what I was asking about. I assumed that periodic modem/radio transactions would keep the SMMU clocked, so would like to get a rough idea of the power savings achieved with this coarse-grained approach. Will -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
