diff mbox series

of: Check 'of_node_reused' flag on of_match_device()

Message ID 20220118173404.1891800-1-robh@kernel.org
State Accepted
Commit 9b22c17a3cc5f61b195da624cbb48634b4e42055
Headers show
Series of: Check 'of_node_reused' flag on of_match_device() | expand

Commit Message

Rob Herring (Arm) Jan. 18, 2022, 5:34 p.m. UTC
Commit 0f153a1b8193 ("usb: chipidea: Set the DT node on the child
device") caused the child device to match on the parent driver
instead of the child's driver since the child's DT node pointer matched.
The worst case result is a loop of the parent driver probing another
instance and creating yet another child device eventually exhausting the
stack. If the child driver happens to match first, then everything works
fine.

A device sharing the DT node should never do DT based driver matching,
so let's simply check of_node_reused in of_match_device() to prevent
that.

Fixes: 0f153a1b8193 ("usb: chipidea: Set the DT node on the child device")
Link: https://lore.kernel.org/all/20220114105620.GK18506@ediswmail.ad.cirrus.com/
Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Chen <peter.chen@nxp.com>
Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/of/device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/of/device.c b/drivers/of/device.c
index b0800c260f64..874f031442dc 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -28,7 +28,7 @@ 
 const struct of_device_id *of_match_device(const struct of_device_id *matches,
 					   const struct device *dev)
 {
-	if ((!matches) || (!dev->of_node))
+	if (!matches || !dev->of_node || dev->of_node_reused)
 		return NULL;
 	return of_match_node(matches, dev->of_node);
 }