* Alan Stern <[email protected]> [190322 20:03]:
> On Fri, 22 Mar 2019, Tony Lindgren wrote:
>
> > * Alan Stern <[email protected]> [190322 18:37]:
> > > How about putting these runtime PM additions into
> > > usb_hcd_platform_shutdown instead, so they will apply to all platform
> > > controller drivers?
> >
> > OK let's do that then.
> >
> > > Also, are you certain you want the pm_runtime_put_sync at the end? If
> > > the system is shutting down anyway, why waste time doing an extra
> > > runtime suspend?
> >
> > Well mostly to keep the calls paired. But maybe there are
> > also kexec reboot cases where we'd want to have things
> > properly disabled for PM before kexec.
>
> I'm not sure that makes sense. You can't actually disable anything for
> runtime PM from within a driver; all you can do is tell the runtime PM
> core that _you're_ not using the device any more. But if some other
> part of the system is still using it, it will remain at full power.
Right, it's just a usecount and whatever happens after that is
ouf of the driver control. And in the shutdown case PM runtime
does not have much of a chance to do anything here :)
Not much point checking the pm_runtime_get_sync() for errors
either then.. We can just add a comment there.
If the patch below looks OK to you I'll post with an updated
description.
Regards,
Tony
8< -------------------
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -3017,6 +3017,9 @@ usb_hcd_platform_shutdown(struct platform_device *dev)
{
struct usb_hcd *hcd = platform_get_drvdata(dev);
+ /* No need for pm_runtime_put(), we're shutting down */
+ pm_runtime_get_sync(&dev->dev);
+
if (hcd->driver->shutdown)
hcd->driver->shutdown(hcd);
}
