On 01/23/2014 12:39 AM, Alexandre Courbot wrote: > On Thu, Jan 23, 2014 at 5:45 AM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: >> On 01/21/2014 03:10 AM, Alexandre Courbot wrote: >>> Invoke the do_idle() firmware call before suspending a CPU so that the >>> underlying firmware (if any) can take necessary action. >> >>> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c >> >>> @@ -45,6 +46,8 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev, >>> >>> clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); >>> >>> + call_firmware_op(do_idle); >>> + >>> cpu_suspend(0, tegra30_sleep_cpu_secondary_finish); >>> >>> clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); >> >> Don't you need to have the kernel also *not* do something when entering >> idle; doesn't the FW op replace some of the register writes that the >> kernel would otherwise be doing? > > It seems like the operation is actually to inform the firmware that we > are going to suspend the CPU. Downstream kernel also uses it that way. > But you are right in that we should expect do_idle() to actually > perform the suspend operation. Maybe a prepare_idle() operation should > be added to the firmware interface for this purpose? That sounds like a reasonable change. Is it easy to plumb in? -- 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
