Hi,

On Thu, Jul 11, 2013 at 02:47:00PM +0530, Rajendra Nayak wrote:
> On Wednesday 10 July 2013 09:37 PM, Felipe Balbi wrote:
> > how about something like below ? It makes omap_device/hwmod and
> > pm_runtime agree on the initial state of the device and will prevent
> > ->runtime_resume() from being called on first pm_runtime_get*() done
> > during probe.
> > 
> > This is similar to what PCI bus does (if you look at pci_pm_init()).
> 
> I tried something similar [1] but what I found is that the serial
> runtime resume was called despite it being marked as active using
> pm_runtime_set_active().
> 
> That seems to be because of the pm_runtime_set_autosuspend_delay()
> because we have the autosuspend_delay = -1
> 
> -----
> static void update_autosuspend(struct device *dev, int old_delay, int old_use)
> {
>         int delay = dev->power.autosuspend_delay;
> 
>         /* Should runtime suspend be prevented now? */
>         if (dev->power.use_autosuspend && delay < 0) {
> 
>                 /* If it used to be allowed then prevent it. */
>                 if (!old_use || old_delay >= 0) {
>                         atomic_inc(&dev->power.usage_count);
>                         rpm_resume(dev, 0); <------------------------------- calls serial runtime resume.
>                 }
>         }
> -----
> 
> So we end up with the same issue with serial resume being called before set_termios()

yeah, that part I figured out after I started testing today. It seems
like my latest version is getting closer but I still see problems, diff
below:

diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index e6d2307..0cc2da9 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -181,6 +181,26 @@ odbfd_exit:
 	return ret;
 }
 
+static void omap_device_pm_init(struct platform_device *pdev)
+{
+	omap_device_enable(pdev);
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	device_enable_async_suspend(&pdev->dev);
+}
+
+static void omap_device_pm_allow(struct platform_device *pdev)
+{
+	pm_runtime_allow(&pdev->dev);
+}
+
+static void omap_device_pm_exit(struct platform_device *pdev)
+{
+	device_disable_async_suspend(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	omap_device_idle(pdev);
+}
+
 static int _omap_device_notifier_call(struct notifier_block *nb,
 				      unsigned long event, void *dev)
 {
@@ -192,16 +212,31 @@ static int _omap_device_notifier_call(struct notifier_block *nb,
 		if (pdev->archdata.od)
 			omap_device_delete(pdev->archdata.od);
 		break;
+	case BUS_NOTIFY_BIND_DRIVER:
+		if (pdev->archdata.od)
+			omap_device_pm_init(pdev);
+		break;
+	case BUS_NOTIFY_BOUND_DRIVER:
+		if (pdev->archdata.od)
+			omap_device_pm_allow(pdev);
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		if (pdev->archdata.od)
+			omap_device_pm_exit(pdev);
+		break;
 	case BUS_NOTIFY_ADD_DEVICE:
 		if (pdev->dev.of_node)
 			omap_device_build_from_dt(pdev);
-		/* fall through */
+		break;
 	default:
-		od = to_omap_device(pdev);
-		if (od)
-			od->_driver_status = event;
+		/* nothing */
+		break;
 	}
 
+	od = to_omap_device(pdev);
+	if (od)
+		od->_driver_status = event;
+
 	return NOTIFY_DONE;
 }
 

-- 
balbi