[PATCH v2 6/6] ARM: tegra: cpuidle: use firmware for power down

On 02/12/2014 10:36 AM, Olof Johansson wrote:

On Fri, Feb 07, 2014 at 01:35:06PM +0900, Alexandre Courbot wrote:

quoted

Attempt to invoke the prepare_idle() and do_idle() firmware calls
to power down a CPU so an underlying firmware gets informed of
the idle operation and performs it by itself if designed in such a way.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
  arch/arm/mach-tegra/cpuidle-tegra114.c | 11 ++++++++++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c
index e0b87300243d..558067ddc186 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra114.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra114.c

@@ -19,6 +19,7 @@
  #include <linux/cpuidle.h>
  #include <linux/cpu_pm.h>
  #include <linux/clockchips.h>
+#include <asm/firmware.h>

  #include <asm/cpuidle.h>
  #include <asm/suspend.h>

@@ -45,7 +46,15 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,

  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);

-	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
+	call_firmware_op(prepare_idle);
+
+	switch (call_firmware_op(do_idle)) {
+	case -ENOSYS:
+		cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
+		break;
+	default:
+		break;

Do you expect other cases down the road? If not, this is a simple if instead:

	/* Only call cpu_suspend if TF didn't handle the pre-suspend logic */
	if (call_firmware_op(do_idle) == -ENOSYS)
		cpu_suspend(....);

I might have been overdoing it indeed. Let me submit a v3 just for this 
one patch.

Thanks!
Alex.