Drivers using pm_runtime_use_autosuspend() may not get disabled after
-EPROBE_DEFER. On the following device driver probe, hardware state
is different from the PM runtime state causing omap_device to produce
the following error:
omap_device_enable() called from invalid state 1
And with omap_device and omap hardware being picky for PM, this will
block any deeper idle states in hardware.
Let's add a proper error message so driver writers can easily fix
their drivers for PM.
In general, the solution is to fix the drivers to follow the PM
runtime documentation:
1. For sections of code that needs the device disabled, use
pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
been set.
2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
set.
Let's not return with 0 from _od_runtime_resume() as that will
eventually lead into new drivers with broken PM runtime that will
block deeper idle states on omaps.
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
Cc: Nishanth Menon <nm@xxxxxx>
Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Tero Kristo <t-kristo@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
arch/arm/mach-omap2/omap_device.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 0437537..ebd8369 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -602,8 +602,10 @@ static int _od_runtime_resume(struct device *dev)
int ret;
ret = omap_device_enable(pdev);
- if (ret)
+ if (ret) {
+ dev_err(dev, "use pm_runtime_put_sync_suspend() in driver?\n");
return ret;
+ }
return pm_generic_runtime_resume(dev);
}
--
2.7.0
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