From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Mon, 11 Nov 2019 09:03:54 +0000 (+0100)
Subject: pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional
X-Git-Tag: v4.9.215~75
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d8c8434dad4d524b80606d8c487808472dc010d3;p=platform%2Fkernel%2Flinux-amlogic.git

pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional

[ Upstream commit 43efdc8f0e6d7088ec61bd55a73bf853f002d043 ]

In the old code (e.g.) mutex_destroy() was called before
pwmchip_remove(). Between these two calls it is possible that a PWM
callback is used which tries to grab the mutex.

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 5ad42f33e70c..2e15acf13893 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -337,6 +337,11 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
 static int pwm_omap_dmtimer_remove(struct platform_device *pdev)
 {
 	struct pwm_omap_dmtimer_chip *omap = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pwmchip_remove(&omap->chip);
+	if (ret)
+		return ret;
 
 	if (pm_runtime_active(&omap->dm_timer_pdev->dev))
 		omap->pdata->stop(omap->dm_timer);
@@ -345,7 +350,7 @@ static int pwm_omap_dmtimer_remove(struct platform_device *pdev)
 
 	mutex_destroy(&omap->mutex);
 
-	return pwmchip_remove(&omap->chip);
+	return 0;
 }
 
 static const struct of_device_id pwm_omap_dmtimer_of_match[] = {