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From:   Arnd Bergmann <arnd@kernel.org>
To:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Nikita Shubin <nikita.shubin@maquefel.me>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Alexander Sverdlin <alexander.sverdlin@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] clocksource: ep93xx: fix error handling during probe
Date:   Tue, 12 Dec 2023 22:46:07 +0100
Message-Id: <20231212214616.193098-1-arnd@kernel.org>
MIME-Version: 1.0
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Precedence: bulk

From: Arnd Bergmann <arnd@arndb.de>

When the interrupt property fails to be parsed, ep93xx_timer_of_init()
return code ends up uninitialized:

drivers/clocksource/timer-ep93xx.c:160:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
        if (irq < 0) {
            ^~~~~~~
drivers/clocksource/timer-ep93xx.c:188:9: note: uninitialized use occurs here
        return ret;
               ^~~
drivers/clocksource/timer-ep93xx.c:160:2: note: remove the 'if' if its condition is always false
        if (irq < 0) {
        ^~~~~~~~~~~~~~

Simplify this portion to use the normal construct of just checking
whether a valid interrupt was returned. Note that irq_of_parse_and_map()
never returns a negative value and no other callers check for that either.

Fixes: c28ca80ba3b5 ("clocksource: ep93xx: Add driver for Cirrus Logic EP93xx")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/clocksource/timer-ep93xx.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/timer-ep93xx.c b/drivers/clocksource/timer-ep93xx.c
index bc0ca6e12334..6981ff3ac8a9 100644
--- a/drivers/clocksource/timer-ep93xx.c
+++ b/drivers/clocksource/timer-ep93xx.c
@@ -155,9 +155,8 @@ static int __init ep93xx_timer_of_init(struct device_node *np)
 	ep93xx_tcu = tcu;
 
 	irq = irq_of_parse_and_map(np, 0);
-	if (irq == 0)
-		irq = -EINVAL;
-	if (irq < 0) {
+	if (!irq) {
+		ret = -EINVAL;
 		pr_err("EP93XX Timer Can't parse IRQ %d", irq);
 		goto out_free;
 	}
-- 
2.39.2