On Friday, April 17, 2015 01:14:15 AM Ben Hutchings wrote: > From: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> > > The sh_eth driver has come up with an issue where the runtime_pm > code suspends it during the probe() method due to the network > device registration re-calling into the driver. > > Add a note about this into the documentation. > > Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> > Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Queued up for 4.2, thanks! > --- > Documentation/power/runtime_pm.txt | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt > index 44fe1d28a163..e76dc0ad4d2b 100644 > --- a/Documentation/power/runtime_pm.txt > +++ b/Documentation/power/runtime_pm.txt > @@ -556,6 +556,12 @@ helper functions described in Section 4. In that case, pm_runtime_resume() > should be used. Of course, for this purpose the device's runtime PM has to be > enabled earlier by calling pm_runtime_enable(). > > +Note, if the device may execute pm_runtime calls during the probe (such as > +if it is registers with a subsystem that may call back in) then the > +pm_runtime_get_sync() call paired with a pm_runtime_put() call will be > +appropriate to ensure that the device is not put back to sleep during the > +probe. This can happen with systems such as the network device layer. > + > It may be desirable to suspend the device once ->probe() has finished. > Therefore the driver core uses the asyncronous pm_request_idle() to submit a > request to execute the subsystem-level idle callback for the device at that > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
