[PATCH 5.5 303/399] pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional

Greg Kroah-Hartman
2020-02-21T07:56:48Z

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ 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>
---
drivers/pwm/pwm-omap-dmtimer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index 6cfeb0e1cc679..e36fcad668a68 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -361,6 +361,11 @@ put:
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[] = {
--
2.20.1