Thread (74 messages) 74 messages, 5 authors, 2016-02-05

PM regression with commit 5de85b9d57ab PM runtime re-init in v4.5-rc1

From: rafael@kernel.org (Rafael J. Wysocki)
Date: 2016-02-01 22:17:54
Also in: linux-omap, linux-pm

On Mon, Feb 1, 2016 at 11:06 PM, Tony Lindgren [off-list ref] wrote:
quoted hunk ↗ jump to hunk
* Tony Lindgren [off-list ref] [160201 10:12]:
quoted
* Ulf Hansson [off-list ref] [160201 08:45]:
quoted
On 28 January 2016 at 17:58, Tony Lindgren [off-list ref] wrote:
quoted
The MMC hardware will not get idled properly any longer blocking any
deeper idle states.
quoted
Did the driver not probe successfully the second try? If so, what happened.
It probes fine after a -EPROBE_DEFER on the vmmc i2c regulator.
But the PM runtime usecounts are wrong.
Okay. How did you verify this?
Well that was just based on what I see in the dmesg:

omap_device: omap_device_enable() called from invalid state 1
So we're now missing the idling of hardare after -EPROBE_DEFER..
Does the following patch work for you guys?

Regards,

Tony

8< -----------------------------
From: Tony Lindgren <tony@atomide.com>
Date: Mon, 1 Feb 2016 13:40:46 -0800
Subject: [PATCH] PM / runtime: Fix PM runtime reinit

Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind") added calls to reinit the PM runtime. This
however broke things for idling the hardware at least if the driver
probing has pm_runtime_set_autosuspend_delay() and -EPROBE_DEFER
happens.

Fix the problem by adding a check for configured autosuspend if
RPM_ACTIVE is set. Then reset the autosuspend, and suspend the
device to make sure the hardware gets idled.

Let's also cut down one level of nestedness and remove a negative
test by returning early if pm_runtime_enabled(dev) as there is
currently nothing for us to do in that case.

Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at
probe error and driver unbind")
Signed-off-by: Tony Lindgren <tony@atomide.com>
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1419,17 +1419,25 @@ void pm_runtime_init(struct device *dev)
  */
 void pm_runtime_reinit(struct device *dev)
 {
-       if (!pm_runtime_enabled(dev)) {
-               if (dev->power.runtime_status == RPM_ACTIVE)
+       if (pm_runtime_enabled(dev))
+               return;
+
+       if (dev->power.runtime_status == RPM_ACTIVE) {
+               if (dev->power.use_autosuspend) {
+                       __pm_runtime_use_autosuspend(dev, false);
+                       pm_runtime_suspend(dev);
This won't work, because runtime PM is disabled at this point.

What about doing this instead:

               if (dev->power.use_autosuspend)
                       __pm_runtime_use_autosuspend(dev, false);

               pm_runtime_set_suspended(dev);

+               } else {
                        pm_runtime_set_suspended(dev);
-               if (dev->power.irq_safe) {
-                       spin_lock_irq(&dev->power.lock);
-                       dev->power.irq_safe = 0;
-                       spin_unlock_irq(&dev->power.lock);
-                       if (dev->parent)
-                               pm_runtime_put(dev->parent);
                }
        }
+
+       if (dev->power.irq_safe) {
+               spin_lock_irq(&dev->power.lock);
+               dev->power.irq_safe = 0;
+               spin_unlock_irq(&dev->power.lock);
+               if (dev->parent)
+                       pm_runtime_put(dev->parent);
+       }
 }

 /**
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