2020-12-10 20:35:37

by Sam Protsenko

[permalink] [raw]
Subject: [PATCH 2/2] usb: dwc3: drd: Avoid error when extcon is missing

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 <[email protected]>
---
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;
--
2.27.0


2020-12-11 14:42:12

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH 2/2] usb: dwc3: drd: Avoid error when extcon is missing

On Thu, Dec 10, 2020 at 10:33:18PM +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().

By some reason you have two separate messages (missed --thread when run `git
format-patch ...`?).

In any case I think it should be dropped or reworked and resent since patch 1/2
got comments.

--
With Best Regards,
Andy Shevchenko


2020-12-12 16:11:25

by Sam Protsenko

[permalink] [raw]
Subject: Re: [PATCH 2/2] usb: dwc3: drd: Avoid error when extcon is missing

Hi Andy,

On Fri, 11 Dec 2020 at 16:15, Andy Shevchenko
<[email protected]> wrote:
>
> On Thu, Dec 10, 2020 at 10:33:18PM +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().
>
> By some reason you have two separate messages (missed --thread when run `git
> format-patch ...`?).
>
> In any case I think it should be dropped or reworked and resent since patch 1/2
> got comments.
>

Yep, the patch version bit shouldn't be there, just forgot to remove
it after `git format-patch'. So this is not a series, just two
separate patches, and 2/2 was just dropped. Anyway, I'll resend this
one soon, to remove the confusing versioning part.

Thanks!

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