release/5.2.40/pwm-omap-dmtimer-Remove-PWM-chip-in-.remove-before-m.patch

From 793dd5d19379dfe909ddfe86068965d4c2eb6c48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Mon, 11 Nov 2019 10:03:54 +0100
Subject: [PATCH] pwm: omap-dmtimer: Remove PWM chip in .remove before making
 it unfunctional
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 43efdc8f0e6d7088ec61bd55a73bf853f002d043 upstream.

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: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 6cfeb0e1cc67..e36fcad668a6 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -361,6 +361,11 @@ 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);
@@ -369,7 +374,7 @@ 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[] = {
-- 
2.7.4