5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Boerge Struempfel <boerge.struempfel@xxxxxxxxx>
[ Upstream commit 95dd1e34ff5bbee93a28ff3947eceaf6de811b1a ]
If gpio_set_transitory() fails, we should free the GPIO again. Most
notably, the flag FLAG_REQUESTED has previously been set in
gpiod_request_commit(), and should be reset on failure.
To my knowledge, this does not affect any current users, since the
gpio_set_transitory() mainly returns 0 and -ENOTSUPP, which is converted
to 0. However the gpio_set_transitory() function calles the .set_config()
function of the corresponding GPIO chip and there are some GPIO drivers in
which some (unlikely) branches return other values like -EPROBE_DEFER,
and -EINVAL. In these cases, the above mentioned FLAG_REQUESTED would not
be reset, which results in the pin being blocked until the next reboot.
Fixes: e10f72bf4b3e ("gpio: gpiolib: Generalise state persistence beyond sleep")
Signed-off-by: Boerge Struempfel <boerge.struempfel@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpio/gpiolib-sysfs.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index fa5d945b2f286..f45ba0f789d4f 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -491,14 +491,17 @@ static ssize_t export_store(struct class *class,
}
status = gpiod_set_transitory(desc, false);
- if (!status) {
- status = gpiod_export(desc, true);
- if (status < 0)
- gpiod_free(desc);
- else
- set_bit(FLAG_SYSFS, &desc->flags);
+ if (status) {
+ gpiod_free(desc);
+ goto done;
}
+ status = gpiod_export(desc, true);
+ if (status < 0)
+ gpiod_free(desc);
+ else
+ set_bit(FLAG_SYSFS, &desc->flags);
+
done:
if (status)
pr_debug("%s: status %d\n", __func__, status);
--
2.42.0
