On Wed, Jan 14, 2015 at 07:57:25AM +0000, Thierry Reding wrote: > On Tue, Jan 13, 2015 at 07:44:50PM +0000, Ian Campbell wrote: > > Hi Thierry, > > > > I needed to boot my Jetson in NS mode (in order to boot Xen) and was > > investigating the possibility of PSCI support when I discovered that you > > had already started on it[0]. Hurrah! > > > > I cherry-picked the relevant commit onto u-boot-tegra#master and added a > > few more patches and now it boots correctly for me, both running Xen > > (some Xen side patches are needed too) and native Linux. > > > > The main things which was needed was to rebase for some recent Kconfig > > changes relating to virt and nonsec mode and to arrange for the RAM used > > by the secure code to be reserved in the FDT. I also reserved the RAM > > using the hardware MC_SECURITY_CFG registers for good measure. > > Great, those were all things that I had wanted to do but never got > around to. > > > I also pushed my tree to gitorious: > > https://gitorious.org/ijc/u-boot jetson-psci-v1 > > > > I would Ack your patch, but I don't think you've posted it and it has no > > S-o-b so that would seem a bit premature/rude of me. For the same reason > > I've not actually included it in the series posted (but it is in the > > gitorious branch). > > Feel free to take ownership of that patch. I currently don't have the > time to work on this and it seems you've made good progress on it. > > It could probably use some cleanup because there's a bit of debug output > still in there. Also... > > > FWIW I think you could drop your stub versions of psci_cpu_off and > > psci_cpu_suspend (assuming you don't want to implement them) since the > > common code has stubs. > > ... I'd think you'd need to implement these so that you can get proper > suspend/resume support in the kernel. I've had to disable cpuidle (via > #undef CONFIG_PM_SLEEP in arch/arm/mach-tegra/cpuidle-tegra114.c) in the > kernel to make that code not powergate CPUs. Ideally I think the kernel > would check that it's running with PSCI support and disable the cpuidle > driver. Maybe that could be done by introducing a new cpuidle driver > that checks for PSCI availability and uses it when present.
We have a generic CPUidle driver on arm64 which can use PSCI as a backend; we should try to reuse that. The binding should certainly be identical. It looks like the tegra124 dts in mainline doesn't use enable-method in the DT, so a better option might be to fail early in cpuidle-tegra114.c if _any_ enable-method is present. Thanks, Mark. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
