linux-kernel - [PATCH][next] pwm: ep93xx: Fix read of uninitialized variable ret

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Date:   Tue, 29 Jun 2021 18:22:53 +0100
From:   Colin King <colin.king@...onical.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>, Lee Jones <lee.jones@...aro.org>,
        linux-pwm@...r.kernel.org
Cc:     kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH][next] pwm: ep93xx: Fix read of uninitialized variable ret

From: Colin Ian King <colin.king@...onical.com>

There is a potential path in function ep93xx_pwm_apply where ret is
never assigned a value and it is checked for an error code. Fix this
by ensuring ret is zero'd in the success path to avoid this issue.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: f6ef94edf0f6 ("pwm: ep93xx: Unfold legacy callbacks into ep93xx_pwm_apply()")
Signed-off-by: Colin Ian King <colin.king@...onical.com>
---
 drivers/pwm/pwm-ep93xx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pwm/pwm-ep93xx.c b/drivers/pwm/pwm-ep93xx.c
index 70fa2957f9d3..8a3d781e6514 100644
--- a/drivers/pwm/pwm-ep93xx.c
+++ b/drivers/pwm/pwm-ep93xx.c
@@ -137,6 +137,7 @@ static int ep93xx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 				writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
 				writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
 			}
+			ret = 0;
 		} else {
 			ret = -EINVAL;
 		}
-- 
2.31.1