On Wed, Jan 16, 2013 at 1:31 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 01/16/2013 11:55 AM, Colin Cross wrote: >> On Wed, Jan 16, 2013 at 12:11 AM, Joseph Lo <josephl@xxxxxxxxxx> wrote: >>> The "powered-down" cpuidle mode of Tegra20 needs the CPU0 be the last one >>> core to go into this mode before other core. The coupled cpuidle framework >>> can help to sync the MPCore to coupled state then go into "powered-down" >>> idle mode together. The driver can just assume the MPCore come into >>> "powered-down" mode at the same time. No need to take care if the CPU_0 >>> goes into this mode along and only can put it into safe idle mode (WFI). >>> >>> The powered-down state of Tegra20 requires power gating both CPU cores. >>> When the secondary CPU requests to enter powered-down state, it saves >>> its own contexts and then enters WFI for waiting CPU0 in the same state. >>> When the CPU0 requests powered-down state, it attempts to put the secondary >>> CPU into reset to prevent it from waking up. Then power down both CPUs >>> together and power off the cpu rail. >>> >>> Be aware of that, you may see the legacy power state "LP2" in the code > > Colin, since you only raised a few small issues on this series, does > that mean you're OK with it once those issues are fixed? I didn't review the Tegra-specific parts careful, but from the coupled cpuidle perspective, with the comments I pointed out, Acked-by: Colin Cross <ccross@xxxxxxxxxxx> > Joseph, we'll be merging Tegra114 in the near future. How will this > patch series affect Tegra114? Will the cpuidle driver simply fail to > register on Tegra114 (which would be fine until we explicitly add > support), or would we need to disable cpuidle in Kconfig to get a > working Tegra114 kernel. Does this patch series affect the answer to the > previous question? Thanks. > -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
