linux-kernel - [PATCH v3 07/12] cdx: Use mutex guard to simplify error handling

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Message-Id: <20260109-of-for-each-compatible-scoped-v3-7-c22fa2c0749a@oss.qualcomm.com>
Date: Fri, 09 Jan 2026 17:57:51 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@....qualcomm.com>
To: Miguel Ojeda <ojeda@...nel.org>, Rob Herring <robh@...nel.org>,
        Saravana Kannan <saravanak@...gle.com>,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <nick.desaulniers+lkml@...il.com>,
        Bill Wendling <morbo@...gle.com>,
        Justin Stitt <justinstitt@...gle.com>,
        Russell King <linux@...linux.org.uk>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Claudiu Beznea <claudiu.beznea@...on.dev>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Madhavan Srinivasan <maddy@...ux.ibm.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Nicholas Piggin <npiggin@...il.com>,
        "Christophe Leroy (CS GROUP)" <chleroy@...nel.org>,
        Nipun Gupta <nipun.gupta@....com>,
        Nikhil Agarwal <nikhil.agarwal@....com>,
        Abel Vesa <abelvesa@...nel.org>, Peng Fan <peng.fan@....com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>, Vinod Koul <vkoul@...nel.org>,
        Sylwester Nawrocki <s.nawrocki@...sung.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>
Cc: linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        llvm@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-clk@...r.kernel.org, imx@...ts.linux.dev,
        dmaengine@...r.kernel.org, linux-media@...r.kernel.org,
        linux-pm@...r.kernel.org,
        Jonathan Cameron <jonathan.cameron@...wei.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@....qualcomm.com>
Subject: [PATCH v3 07/12] cdx: Use mutex guard to simplify error handling

Mutex guard allows to drop one goto/break in error handling and the
less expected code of assigning -EINVAL to unsigned size_t count
variable.

Suggested-by: Jonathan Cameron <jonathan.cameron@...wei.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@....qualcomm.com>
---
 drivers/cdx/cdx.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index bbde529aaa93..588dd12e8105 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -616,7 +616,7 @@ static ssize_t rescan_store(const struct bus_type *bus,
 	if (!val)
 		return -EINVAL;
 
-	mutex_lock(&cdx_controller_lock);
+	guard(mutex)(&cdx_controller_lock);
 
 	/* Unregister all the devices on the bus */
 	cdx_unregister_devices(&cdx_bus_type);
@@ -624,10 +624,8 @@ static ssize_t rescan_store(const struct bus_type *bus,
 	/* Rescan all the devices */
 	for_each_compatible_node_scoped(np, NULL, compat_node_name) {
 		pd = of_find_device_by_node(np);
-		if (!pd) {
-			count = -EINVAL;
-			goto unlock;
-		}
+		if (!pd)
+			return -EINVAL;
 
 		cdx = platform_get_drvdata(pd);
 		if (cdx && cdx->controller_registered && cdx->ops->scan)
@@ -636,9 +634,6 @@ static ssize_t rescan_store(const struct bus_type *bus,
 		put_device(&pd->dev);
 	}
 
-unlock:
-	mutex_unlock(&cdx_controller_lock);
-
 	return count;
 }
 static BUS_ATTR_WO(rescan);

-- 
2.51.0