On Thu, Jul 21, 2016 at 4:27 PM, Helmut Grohne [off-list ref] wrote:

On Fri, Jul 08, 2016 at 10:23:07AM +0200, Shubhrajyoti Datta wrote:

quoted

 A small issue

Now it will be off by 1 ie we enable twice in probe.

solution is that either there should be get_sync or clk_enable but not both.

As far as I understand the inner workings of pm_runtime_get_sync this is
not a problem.

the issue is not with the runtime.

quoted

quoted

+       ret = clk_prepare_enable(gpio->clk);
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to enable clock.\n");
+               return ret;
+       }

This will now enable the first time.

quoted

+       pm_runtime_set_active(&pdev->dev);

the the pm core that it is enabled .

This function sets pdev->dev.power.runtime_status to RPM_ACTIVE (via
__update_runtime_status).

quoted

quoted

        pm_runtime_enable(&pdev->dev);
        ret = pm_runtime_get_sync(&pdev->dev);

this will enable the second time.

The bulk of the work is done by rpm_resume. Close to the top of the
function the runtime_status field is compared to RPM_ACTIVE and if so,
the resume operation is skipped.

Is there any mistake in that analysis?

I feel that if you can print the clk enable count in at boot things
could be easy
to understand.

Helmut