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* [PATCH 1/2] USB: ehci-platform: fix companion-device leak
@ 2017-05-16 14:26 Johan Hovold
  2017-05-17  4:53 ` Yoshihiro Shimoda
  0 siblings, 1 reply; 4+ messages in thread
From: Johan Hovold @ 2017-05-16 14:26 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Alan Stern, linux-usb, Johan Hovold, stable, Yoshihiro Shimoda

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@vger.kernel.org>     # 4.11
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 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);
+	}
 
 	ehci_resume(hcd, priv->reset_on_resume);
 	return 0;
-- 
2.13.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* RE: [PATCH 1/2] USB: ehci-platform: fix companion-device leak
  2017-05-16 14:26 [PATCH 1/2] USB: ehci-platform: fix companion-device leak Johan Hovold
@ 2017-05-17  4:53 ` Yoshihiro Shimoda
  2017-05-17  8:59   ` Johan Hovold
  0 siblings, 1 reply; 4+ messages in thread
From: Yoshihiro Shimoda @ 2017-05-17  4:53 UTC (permalink / raw)
  To: Johan Hovold, Greg Kroah-Hartman; +Cc: Alan Stern, linux-usb, stable

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@vger.kernel.org>     # 4.11
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  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.

So,

Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Best regards,
Yoshihiro Shimoda

>  	ehci_resume(hcd, priv->reset_on_resume);
>  	return 0;
> --
> 2.13.0

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] USB: ehci-platform: fix companion-device leak
  2017-05-17  4:53 ` Yoshihiro Shimoda
@ 2017-05-17  8:59   ` Johan Hovold
  2017-05-18  1:50     ` Yoshihiro Shimoda
  0 siblings, 1 reply; 4+ messages in thread
From: Johan Hovold @ 2017-05-17  8:59 UTC (permalink / raw)
  To: Yoshihiro Shimoda
  Cc: Johan Hovold, Greg Kroah-Hartman, Alan Stern, linux-usb, stable

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@vger.kernel.org>     # 4.11
> > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > Signed-off-by: Johan Hovold <johan@kernel.org>
> > ---
> >  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.

> So,
> 
> Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Thanks,
Johan

^ permalink raw reply	[flat|nested] 4+ messages in thread
* RE: [PATCH 1/2] USB: ehci-platform: fix companion-device leak
  2017-05-17  8:59   ` Johan Hovold
@ 2017-05-18  1:50     ` Yoshihiro Shimoda
  0 siblings, 0 replies; 4+ messages in thread
From: Yoshihiro Shimoda @ 2017-05-18  1:50 UTC (permalink / raw)
  To: Johan Hovold; +Cc: Greg Kroah-Hartman, Alan Stern, linux-usb, stable

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@vger.kernel.org>     # 4.11
> > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > Signed-off-by: Johan Hovold <johan@kernel.org>
> > > ---
> > >  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

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-05-18  1:50 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-05-16 14:26 [PATCH 1/2] USB: ehci-platform: fix companion-device leak Johan Hovold
2017-05-17  4:53 ` Yoshihiro Shimoda
2017-05-17  8:59   ` Johan Hovold
2017-05-18  1:50     ` Yoshihiro Shimoda

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