Since pinctrl_gpio_direction() takes a mutex, the gpio driver must
have can_sleep set to true. If not, then this function will call
WARN_ON (only once per pin controller) to tell the developer that
something must be done: either set can_sleep to true, or set the
direction in the combine gpio/pinctrl driver itself without calling
pinctrl_gpio_direction_input/output.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
drivers/pinctrl/core.c | 11 +++++++++++
drivers/pinctrl/core.h | 4 ++++
2 files changed, 15 insertions(+)
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index ffe39336fcac..886242d08dcf 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -845,6 +845,17 @@ static int pinctrl_gpio_direction(unsigned gpio, bool input)
mutex_lock(&pctldev->mutex);
+ if (!pctldev->checked_can_sleep) {
+ struct gpio_chip *chip = gpio_to_chip(gpio);
+
+ pctldev->checked_can_sleep = true;
+ /*
+ * This pin controller can sleep, so check that the gpio
+ * controller sets can_sleep to true.
+ */
+ WARN_ON(chip && !chip->can_sleep);
+ }
+
/* Convert to the pin controllers number space */
pin = gpio_to_pin(range, gpio);
ret = pinmux_gpio_direction(pctldev, range, pin, input);
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 840103c40c14..ae14b4e69b7b 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -38,6 +38,9 @@ struct pinctrl_gpio_range;
* @hog_sleep: sleep state for pins hogged by this device
* @mutex: mutex taken on each pin controller specific action
* @device_root: debugfs root for this device
+ * @checked_can_sleep: used internally to warn once if pinctrl_gpio_direction()
+ * is called from a gpio driver that didn't set @can_sleep to true.
+ * pinctrl_gpio_direction() uses mutexes, so it can sleep.
*/
struct pinctrl_dev {
struct list_head node;
@@ -62,6 +65,7 @@ struct pinctrl_dev {
#ifdef CONFIG_DEBUG_FS
struct dentry *device_root;
#endif
+ bool checked_can_sleep;
};
/**
--
2.33.0
