This is a note to let you know that I've just added the patch titled pwm: img: Fix null pointer access in probe to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pwm-img-fix-null-pointer-access-in-probe.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b261b53539d8070d58dce7597a01d2067d5327ae Author: Hauke Mehrtens <hauke@xxxxxxxxxx> Date: Thu Aug 20 19:14:25 2020 +0200 pwm: img: Fix null pointer access in probe [ Upstream commit b39c0615d0667b3a6f2f5c4bf99ffadf3b518bb1 ] 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@xxxxxxxxxx> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx> Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c index 599a0f66a3845..a34d95ed70b20 100644 --- 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: