pwm: mediatek: Ensure to disable clocks in error path

commit 505b730ede7f5c4083ff212aa955155b5b92e574 upstream.

After enabling the clocks each error path must disable the clocks again.
One of them failed to do so. Unify the error paths to use goto to make it
harder for future changes to add a similar bug.

Fixes: 7ca59947b5fc ("pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250704172728.626815-2-u.kleine-koenig@baylibre.com
Cc: stable@vger.kernel.org
[ukleinek: backported to 5.15.y]
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index 1879ce5b3ff29a18d214364fc7cde97401ba05e1..3cf766d892dbb979826e2cc52ff79e36cff8fc58 100644 (file)
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -134,8 +134,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
                return ret;
 
        clk_rate = clk_get_rate(pc->clk_pwms[pwm->hwpwm]);
-       if (!clk_rate)
-               return -EINVAL;
+       if (!clk_rate) {
+               ret = -EINVAL;
+               goto out;
+       }
 
        /* Make sure we use the bus clock and not the 26MHz clock */
        if (pc->soc->has_ck_26m_sel)
@@ -154,9 +156,9 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
        }
 
        if (clkdiv > PWM_CLK_DIV_MAX) {
-               pwm_mediatek_clk_disable(chip, pwm);
-               dev_err(chip->dev, "period %d not supported\n", period_ns);
-               return -EINVAL;
+               dev_err(chip->dev, "period of %d ns not supported\n", period_ns);
+               ret = -EINVAL;
+               goto out;
        }
 
        if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
@@ -173,9 +175,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
        pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
        pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
 
+out:
        pwm_mediatek_clk_disable(chip, pwm);
 
-       return 0;
+       return ret;
 }
 
 static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)