Hi Ulf,

On 10/23/2014 11:11 AM, Ulf Hansson wrote:

On 22 October 2014 17:44, Geert Uytterhoeven [off-list ref] wrote:

quoted

On Wed, Oct 22, 2014 at 5:28 PM, Ulf Hansson [off-list ref] wrote:

quoted

On 22 October 2014 17:09, Geert Uytterhoeven [off-list ref] wrote:

quoted

On Wed, Oct 22, 2014 at 5:01 PM, Ulf Hansson [off-list ref] wrote:

quoted

quoted

quoted

quoted

+void keystone_pm_domain_attach_dev(struct device *dev)
   {
+    struct clk *clk;
       int ret;
+    int i = 0;

       dev_dbg(dev, "%s\n", __func__);

-    ret = pm_generic_runtime_suspend(dev);
-    if (ret)
-        return ret;
-
-    ret = pm_clk_suspend(dev);
+    ret = pm_clk_create(dev);
       if (ret) {
-        pm_generic_runtime_resume(dev);
-        return ret;
+        dev_err(dev, "pm_clk_create failed %d\n", ret);
+        return;
+    };
+
+    while ((clk = of_clk_get(dev->of_node, i++)) && !IS_ERR(clk)) {
+        ret = pm_clk_add_clk(dev, clk);
+        if (ret) {
+            dev_err(dev, "pm_clk_add_clk failed %d\n", ret);
+            goto clk_err;
+        };
       }

-    return 0;
+    if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {

Can we not okkup two seperate callbacks instead of above check ?
I don't like this CONFIG check here. Its slightly better version of
ifdef in middle of the code.

I've found more-less similar comment on patch
"Re: [PATCH v3 1/3] power-domain: add power domain drivers for Rockchip platform"
https://lkml.org/lkml/2014/10/17/257

So, Would you like me to create patch which will enable clocks in pm_clk_add/_clk()
in case !IS_ENABLED(CONFIG_PM_RUNTIME)

I am wondering whether we actually should/could do this, no matter of
CONFIG_PM_RUNTIME.

Typically, for configurations that uses CONFIG_PM_RUNTIME, the PM
clocks through pm_clk_suspend(), will be gated once the device becomes
runtime PM suspended. Right?

Doing it unconditionally means we'll have lots of unneeded clocks running
for a short while.

quoted

As long as the pm_clk_add() is being invoked from the ->attach_dev()
callback, we are in the probe path. Certainly we would like to have
clocks enabled while probing, don't you think?

If we wouldn't enable the clocks for CONFIG_PM_RUNTIME, when will
those be enabled?

They will be enabled when the driver does

         pm_runtime_enable(dev);
         pm_runtime_get_sync(dev);

in its .probe() method.

No! This doesn't work for drivers which have used
pm_runtime_set_active() prior pm_runtime_enable().

Sorry, but some misunderstanding is here:
1) If some code call pm_runtime_set_active() it has to ensure
that all PM resources switched to ON state. All! So, it will 
be ok to call enable & get after that - these functions will only 
adjust counters.

2) if CONFIG_PM_RUNTIME=n the pm_runtime_set_active() will
be empty (see pm_runtime.h) and you can't relay on it.

3) if CONFIG_PM_RUNTIME=n the pm_runtime_enable/disable() will
be empty - and disable_depth == 1 all the time.

In my case, the combination of generic PD and PM clock framework
will do everything I need for both cases CONFIG_PM_RUNTIME=y/n.

PM domain attach_dev/detach_dev callbacks - will fill PM resources
and enable them if CONFIG_PM_RUNTIME=n.

if CONFIG_PM_RUNTIME - PM resources will be enabled/disabled
by Runtime PM through .start()/.stop() callbacks.

And seems suspend/resume will work too - can't try it now, but it
should work, because .start()/.stop() callbacks have to be called
from pm_genpd_suspend_noirq.

That should also be a common good practice for most drivers, otherwise
they wouldn?t work unless CONFIG_PM_RUNTIME is enabled.

Please have a look at the following patchset, which is fixing up one
driver to behave better.
http://marc.info/?l=linux-pm&m=141327095713390&w=2

It always was (and seems will) a big challenge to support both
CONFIG_PM_RUNTIME=y and system suspend in drivers ;), especially if driver was
initially created using Runtime PM centric approach.

But, for the case CONFIG_PM_RUNTIME + !CONFIG_PM_RUNTIME + suspend...
It will be painful :..((


For example your patches (may be I'm not fully understand your problem, 
so here are just comments to code):
patch 3:
  - I think you can do smth like this in probe 
        ret = pm_runtime_get_sync(&pdev->dev);
        if (ret < 0)
                goto err_m2m;
+       
+       if (!pm_runtime_enabled(dev)) {
+               gsc_runtime_resume(dev);
+       } 

 - and similar thing in remove, before pm_runtime_disable
 
patch 5 - pm_runtime_force_suspend/resume() will not take into
account or change Runtime PM state of the device if !CONFIG_PM_RUNTIME.
runtime_status == RPM_SUSPENDED always in this case!
So, there may be some side-effects.

patch 7 - you can't call clk_prepare/unprepare from Runtime PM
callbacks, because they aren't atomic

Oh, You definitely will be enjoyed ;)

regards,
-grygorii