summaryrefslogtreecommitdiffstats
path: root/drivers/pwm
diff options
context:
space:
mode:
authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2021-09-09 11:48:49 +0200
committerThierry Reding <thierry.reding@gmail.com>2021-11-05 11:51:41 +0100
commit4ad91a227817ae48f931595d1101fc7100073ce9 (patch)
tree66c8a2c4961fcd269c3e933e8a2cb11a5ca7f5fa /drivers/pwm
parent27d9a4d69433af1827a764fe235866d5d5501fdb (diff)
downloadlinux-4ad91a227817ae48f931595d1101fc7100073ce9.tar.bz2
pwm: Make it explicit that pwm_apply_state() might sleep
At least some implementations sleep. So mark pwm_apply_state() with a might_sleep() to make callers aware. In the worst case this uncovers a valid atomic user, then we revert this patch and at least gained some more knowledge and then can work on a concept similar to gpio_get_value/gpio_get_value_cansleep. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/core.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 4527f09a5c50..fb04a439462c 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -532,6 +532,15 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
struct pwm_chip *chip;
int err;
+ /*
+ * Some lowlevel driver's implementations of .apply() make use of
+ * mutexes, also with some drivers only returning when the new
+ * configuration is active calling pwm_apply_state() from atomic context
+ * is a bad idea. So make it explicit that calling this function might
+ * sleep.
+ */
+ might_sleep();
+
if (!pwm || !state || !state->period ||
state->duty_cycle > state->period)
return -EINVAL;