Hi Johan,
> -----Original Message-----
> From: Johan Hovold
> Sent: Wednesday, May 17, 2017 6:00 PM
>
> On Wed, May 17, 2017 at 04:53:07AM +0000, Yoshihiro Shimoda wrote:
> > Hi Johan,
> >
> > > From: Johan Hovold
> > > Sent: Tuesday, May 16, 2017 11:26 PM
> > >
> > > Make sure do drop the reference taken to the companion device during
> > > resume.
> > >
> > > Fixes: d4d75128b8fd ("usb: host: ehci-platform: fix usb 1.1 device is not connected in system resume")
> > > Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.11
> > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> > > ---
> > > drivers/usb/host/ehci-platform.c | 4 +++-
> > > 1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> > > index bc7b9be12f54..f1908ea9fbd8 100644
> > > --- a/drivers/usb/host/ehci-platform.c
> > > +++ b/drivers/usb/host/ehci-platform.c
> > > @@ -384,8 +384,10 @@ static int ehci_platform_resume(struct device *dev)
> > > }
> > >
> > > companion_dev = usb_of_get_companion_dev(hcd->self.controller);
> > > - if (companion_dev)
> > > + if (companion_dev) {
> > > device_pm_wait_for_dev(hcd->self.controller, companion_dev);
> > > + put_device(companion_dev);
> >
> > Thank you for the patch!
> >
> > I should have added an API like "usb_of_put_companion_dev(dev)"
> > and it calls "of_dev_put(to_platform_device(dev))". And then,
> > ehci_platform_resume() can call the API instead of put_device().
> > But, adding new API is not good for stable.
>
> I don't think that's needed or desirable. The helper returns a pointer
> to a struct device with an incremented refcount, so just using
> put_device() when done is the right thing to do.
>
> Note that I added a comment about the refcount to the helper in patch
> 2/2 as a reminder for any future users.
Thank you for the reply!
I understood it and I agreed with you!
Best regards,
Yoshihiro Shimoda