From:   Daniel Scally <djrscally@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     gregkh@linuxfoundation.org, rafael@kernel.org,
        andriy.shevchenko@linux.intel.com, hdegoede@redhat.com
Subject: [PATCH v2] device property: Check fwnode->secondary when finding properties
Date:   Sun, 28 Nov 2021 23:24:55 +0000
Message-Id: <20211128232455.39332-1-djrscally@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

fwnode_property_get_reference_args() searches for named properties
against a fwnode_handle, but these could instead be against the fwnode's
secondary. If the property isn't found against the primary, check the
secondary to see if it's there instead.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
---
Changes since v1: 

	- Added !IS_ERR_OR_NULL(fwnode) to the if guard to protect against
	null pointer dereference.

 drivers/base/property.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index f1f35b48ab8b..11e3d6308eb0 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -478,8 +478,17 @@ int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
 				       unsigned int nargs, unsigned int index,
 				       struct fwnode_reference_args *args)
 {
-	return fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
-				  nargs, index, args);
+	int ret;
+
+	ret = fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
+				 nargs, index, args);
+
+	if (ret < 0 && !IS_ERR_OR_NULL(fwnode) &&
+	    !IS_ERR_OR_NULL(fwnode->secondary))
+		ret = fwnode_call_int_op(fwnode->secondary, get_reference_args,
+					 prop, nargs_prop, nargs, index, args);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args);
 
-- 
2.25.1