Messages in this thread | | | From | "dbasehore ." <> | Date | Thu, 30 Nov 2017 17:21:20 -0800 | Subject | Re: Save and Restore Generic Interrupt Controller for System Sleep on ARM |
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On Thu, Nov 30, 2017 at 1:44 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: > On Wed, Nov 29 2017 at 2:49:18 pm GMT, "dbasehore ." <dbasehore@chromium.org> wrote: >> There was some work in ARM Trusted Firmware to support saving and >> restoring the Generic Interrupt Controller (GICv3) before and after >> sleep, but it seems that the plan is to have this all in the kernel >> now. The point of doing this is to save power during sleep. On an >> RK3399 system, we save about 15mW by disabling the power rail that the >> GIC is on. >> >> I was looking for whether anyone had anything in progress already or >> for preferences on how to do this. Marc suggested using a device tree >> entry to indicate the need to save and restore the GIC. There is >> another requirement to resend MAPC commands on certain implementations >> of the GICv3 which could be indicated by another device tree entry. > > Let's be precise: This is a GIC-500 requirement, and not something that > the GICv3 architecture defines (PM is *not* part of the GICv3 > architecture). >
Just to double check, do the register restores apply to all GICv3 designs? If so, I can put that code in the gic-v3 code instead of breaking it out.
>> If someone does have patches, I'll be able to test and verify them on >> my system since we've gotten things working with the ARM Trusted >> Firmware patches. > > I'm not aware of any such patch that has been posted for mainline, so > just post whatever you have and we'll take it from there. > > IT is hard to comment further on what you're trying to do without seeing > the code and a description of the new API between ATF and the kernel. > > Thanks, > > M. > -- > Jazz is not dead, it just smell funny.
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