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* [PATCH] usb: dwc3: drd: Avoid error when extcon is missing
@ 2020-12-11 14:24 Sam Protsenko
  2020-12-11 14:49 ` Andy Shevchenko
  0 siblings, 1 reply; 3+ messages in thread
From: Sam Protsenko @ 2020-12-11 14:24 UTC (permalink / raw)
  To: linux-usb, linux-kernel
  Cc: Felipe Balbi, Greg Kroah-Hartman, John Stultz, Andy Shevchenko

If "port" node is missing in PHY controller node, dwc3_get_extcon()
isn't able to find extcon device. This is perfectly fine in case when
"usb-role-switch" or OTG is used, but next misleading error message is
printed in that case, from of_graph_get_remote_node():

    OF: graph: no port node found in /phy@1234abcd

Avoid printing that message by checking if port node exists in PHY node
before calling of_graph_get_remote_node().

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/usb/dwc3/drd.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 3e1c1aacf002..eaf389d3f3c5 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -441,8 +441,8 @@ static int dwc3_drd_notifier(struct notifier_block *nb,
 static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 {
 	struct device *dev = dwc->dev;
-	struct device_node *np_phy, *np_conn;
-	struct extcon_dev *edev;
+	struct device_node *np_phy;
+	struct extcon_dev *edev = NULL;
 	const char *name;
 
 	if (device_property_read_bool(dev, "extcon"))
@@ -462,15 +462,22 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 		return edev;
 	}
 
+	/*
+	 * Try to get extcon device from USB PHY controller's "port" node.
+	 * Check if it has the "port" node first, to avoid printing the error
+	 * message from underlying code, as it's a valid case: extcon device
+	 * (and "port" node) may be missing in case of "usb-role-switch" or OTG
+	 * mode.
+	 */
 	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
-	np_conn = of_graph_get_remote_node(np_phy, -1, -1);
+	if (of_graph_is_present(np_phy)) {
+		struct device_node *np_conn;
 
-	if (np_conn)
-		edev = extcon_find_edev_by_node(np_conn);
-	else
-		edev = NULL;
-
-	of_node_put(np_conn);
+		np_conn = of_graph_get_remote_node(np_phy, -1, -1);
+		if (np_conn)
+			edev = extcon_find_edev_by_node(np_conn);
+		of_node_put(np_conn);
+	}
 	of_node_put(np_phy);
 
 	return edev;
-- 
2.29.2


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] usb: dwc3: drd: Avoid error when extcon is missing
  2020-12-11 14:24 [PATCH] usb: dwc3: drd: Avoid error when extcon is missing Sam Protsenko
@ 2020-12-11 14:49 ` Andy Shevchenko
  2020-12-11 21:14   ` Sam Protsenko
  0 siblings, 1 reply; 3+ messages in thread
From: Andy Shevchenko @ 2020-12-11 14:49 UTC (permalink / raw)
  To: Sam Protsenko
  Cc: linux-usb, linux-kernel, Felipe Balbi, Greg Kroah-Hartman, John Stultz

On Fri, Dec 11, 2020 at 04:24:21PM +0200, Sam Protsenko wrote:
> If "port" node is missing in PHY controller node, dwc3_get_extcon()
> isn't able to find extcon device. This is perfectly fine in case when
> "usb-role-switch" or OTG is used, but next misleading error message is
> printed in that case, from of_graph_get_remote_node():
> 
>     OF: graph: no port node found in /phy@1234abcd
> 
> Avoid printing that message by checking if port node exists in PHY node
> before calling of_graph_get_remote_node().

So, this has to be v2...
Anyway, see below.

...

>  static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
>  {
>  	struct device *dev = dwc->dev;
> -	struct device_node *np_phy, *np_conn;
> -	struct extcon_dev *edev;
> +	struct device_node *np_phy;
> +	struct extcon_dev *edev = NULL;
>  	const char *name;
>  
>  	if (device_property_read_bool(dev, "extcon"))
> @@ -462,15 +462,22 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
>  		return edev;
>  	}
>  
> +	/*
> +	 * Try to get extcon device from USB PHY controller's "port" node.
> +	 * Check if it has the "port" node first, to avoid printing the error
> +	 * message from underlying code, as it's a valid case: extcon device
> +	 * (and "port" node) may be missing in case of "usb-role-switch" or OTG
> +	 * mode.
> +	 */
>  	np_phy = of_parse_phandle(dev->of_node, "phys", 0);
> -	np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> +	if (of_graph_is_present(np_phy)) {
> +		struct device_node *np_conn;
>  
> -	if (np_conn)
> -		edev = extcon_find_edev_by_node(np_conn);
> -	else
> -		edev = NULL;
> -
> -	of_node_put(np_conn);
> +		np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> +		if (np_conn)
> +			edev = extcon_find_edev_by_node(np_conn);
> +		of_node_put(np_conn);
> +	}
>  	of_node_put(np_phy);
>  
>  	return edev;


Why not do it slightly different, i.e.

-	np_conn = of_graph_get_remote_node(np_phy, -1, -1);
+	if (of_graph_is_present(np_phy))
+		np_conn = of_graph_get_remote_node(np_phy, -1, -1);
+	else
+		np_conn = NULL;

?

-- 
With Best Regards,
Andy Shevchenko



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] usb: dwc3: drd: Avoid error when extcon is missing
  2020-12-11 14:49 ` Andy Shevchenko
@ 2020-12-11 21:14   ` Sam Protsenko
  0 siblings, 0 replies; 3+ messages in thread
From: Sam Protsenko @ 2020-12-11 21:14 UTC (permalink / raw)
  To: Andy Shevchenko
  Cc: linux-usb, linux-kernel, Felipe Balbi, Greg Kroah-Hartman, John Stultz

On Fri, 11 Dec 2020 at 16:48, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Dec 11, 2020 at 04:24:21PM +0200, Sam Protsenko wrote:
> > If "port" node is missing in PHY controller node, dwc3_get_extcon()
> > isn't able to find extcon device. This is perfectly fine in case when
> > "usb-role-switch" or OTG is used, but next misleading error message is
> > printed in that case, from of_graph_get_remote_node():
> >
> >     OF: graph: no port node found in /phy@1234abcd
> >
> > Avoid printing that message by checking if port node exists in PHY node
> > before calling of_graph_get_remote_node().
>
> So, this has to be v2...
> Anyway, see below.
>
> ...
>
> >  static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
> >  {
> >       struct device *dev = dwc->dev;
> > -     struct device_node *np_phy, *np_conn;
> > -     struct extcon_dev *edev;
> > +     struct device_node *np_phy;
> > +     struct extcon_dev *edev = NULL;
> >       const char *name;
> >
> >       if (device_property_read_bool(dev, "extcon"))
> > @@ -462,15 +462,22 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
> >               return edev;
> >       }
> >
> > +     /*
> > +      * Try to get extcon device from USB PHY controller's "port" node.
> > +      * Check if it has the "port" node first, to avoid printing the error
> > +      * message from underlying code, as it's a valid case: extcon device
> > +      * (and "port" node) may be missing in case of "usb-role-switch" or OTG
> > +      * mode.
> > +      */
> >       np_phy = of_parse_phandle(dev->of_node, "phys", 0);
> > -     np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> > +     if (of_graph_is_present(np_phy)) {
> > +             struct device_node *np_conn;
> >
> > -     if (np_conn)
> > -             edev = extcon_find_edev_by_node(np_conn);
> > -     else
> > -             edev = NULL;
> > -
> > -     of_node_put(np_conn);
> > +             np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> > +             if (np_conn)
> > +                     edev = extcon_find_edev_by_node(np_conn);
> > +             of_node_put(np_conn);
> > +     }
> >       of_node_put(np_phy);
> >
> >       return edev;
>
>
> Why not do it slightly different, i.e.
>
> -       np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> +       if (of_graph_is_present(np_phy))
> +               np_conn = of_graph_get_remote_node(np_phy, -1, -1);
> +       else
> +               np_conn = NULL;
>
> ?
>

Thanks for the review, Andy! I'll address this in v3.

> --
> With Best Regards,
> Andy Shevchenko
>
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-12-12  1:01 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-12-11 14:24 [PATCH] usb: dwc3: drd: Avoid error when extcon is missing Sam Protsenko
2020-12-11 14:49 ` Andy Shevchenko
2020-12-11 21:14   ` Sam Protsenko

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