pwm: img: Fix null pointer access in probe

dev_get_drvdata() is called in img_pwm_runtime_resume() before the
driver data is set.
When pm_runtime_enabled() returns false in img_pwm_probe() it calls
img_pwm_runtime_resume() which results in a null pointer access.

This patch fixes the problem by setting the driver data earlier in the
img_pwm_probe() function.

This crash was seen when booting the Imagination Technologies Creator
Ci40 (Marduk) with kernel 5.4 in OpenWrt.

Fixes: e690ae526216 ("pwm: img: Add runtime PM")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index 599a0f6..a34d95e 100644 (file)
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c
@@ -277,6 +277,8 @@ static int img_pwm_probe(struct platform_device *pdev)
                return PTR_ERR(pwm->pwm_clk);
        }
 
+       platform_set_drvdata(pdev, pwm);
+
        pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT);
        pm_runtime_use_autosuspend(&pdev->dev);
        pm_runtime_enable(&pdev->dev);
@@ -313,7 +315,6 @@ static int img_pwm_probe(struct platform_device *pdev)
                goto err_suspend;
        }
 
-       platform_set_drvdata(pdev, pwm);
        return 0;
 
 err_suspend: