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? -- 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
