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> --- 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 -- 1.7.10.4 -- 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
