Hi Geert, On 23/02/17 15:34, Geert Uytterhoeven wrote: > Hi Sudeep, > > On Thu, Feb 23, 2017 at 4:26 PM, Geert Uytterhoeven > <geert@xxxxxxxxxxxxxx> wrote: >> On Wed, Feb 22, 2017 at 3:32 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: >>> On 22/02/17 13:38, Geert Uytterhoeven wrote: >>>> On Wed, Feb 22, 2017 at 12:03 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: >>>> 4. Patch 3/6 adds a new "shallow" state, as it allows to save more >>>> power (the difference may be due to suboptimal cpuidle platform support on R-Car Gen3, though), >>> >>> Why can't you do that in s2idle mode. Please give me the difference >>> between your shallow state and s2idle state, not just power numbers >>> but the actual state of CPUs and the devices in the system. >> >> From the Linux side, there's not much difference, except that the secondary >> CPU cores are disabled. As that is handled by PSCI, the difference may be >> in the PSCI implementation. I will have to check that... >> >> On these SoCs, the individual CPU cores and the SCU/L2 are in separate >> (nested) power areas. Perhaps these power areas are turned off when >> disabling the CPU cores, but not when suspending them. > > BTW, I don't care much about the extra state. > Then stop caring about extra power usage too ;). Seriously this is not a valid argument. >>>> E.g. on non-PSCI platforms with an Ethernet driver that supports >>>> Wake-on-LAN, I can do: >>>> >>>> ethtool -s eth0 wol g >>>> echo mem > /sys/power/state >>>> >>>> and be sure that the system can be woken up by sending a WoL MagicPacket. >>> >>> Still possible with s2idle if CPU_SUSPEND is correctly implemented by >>> the platform. >> >> Sure. But not automatic, as it needs fiddling with mem_sleep. > > I do care about this, as it affects user experience. > Again when you have both "deep" and "standby" suspend states as per your patch set, user has to choose one. No escape from that. -- Regards, Sudeep
