[PATCH v1 0/1] gpio: cdev: EOPNOTSUPP when HTE unavailable

[PATCH v1 0/1] gpio: cdev: EOPNOTSUPP when HTE unavailable

[Iván Ezequiel Rodriguez]

Hi,

When CONFIG_HTE is enabled but hte_ts_get() returns -ENODEV (no HTE
provider for the line), gpiolib-cdev currently propagates -ENODEV to
userspace.

Map that to -EOPNOTSUPP so it matches the errno already returned when
CONFIG_HTE is disabled or GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE is
otherwise unsupported.

Base: v7.3-rc1

Tested: built with CONFIG_GPIOLIB=y, CONFIG_GPIO_CDEV=y, CONFIG_HTE=y.
QEMU smoke for the HTE ioctl path was skipped (no gpiochip0 in this
guest); the change is a one-line errno remap on the existing error
path.

Thanks,
Iván

Iván Ezequiel Rodriguez (1):
  gpio: cdev: return EOPNOTSUPP when HTE is unavailable

 drivers/gpio/gpiolib-cdev.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
2.43.0

[PATCH v1 1/1] gpio: cdev: return EOPNOTSUPP when HTE is unavailable

[Iván Ezequiel Rodriguez]

Map hte_ts_get() -ENODEV to -EOPNOTSUPP so userspace sees the same
errno as when CONFIG_HTE is disabled or EVENT_CLOCK_HTE is unsupported.

Signed-off-by: Iván Ezequiel Rodriguez <ivanrwcm25@gmail.com>
---
 drivers/gpio/gpiolib-cdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 9f3b628d5793..6dc01f7ea838 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -715,6 +715,8 @@ static int hte_edge_setup(struct line *line, u64 eflags)
 			   line->desc);
 
 	ret = hte_ts_get(NULL, hdesc, 0);
+	if (ret == -ENODEV)
+		return -EOPNOTSUPP;
 	if (ret)
 		return ret;
 
-- 
2.43.0

Re: [PATCH v1 1/1] gpio: cdev: return EOPNOTSUPP when HTE is unavailable

[Bartosz Golaszewski]

On Mon, 31 Aug 2026 12:23:06 -0300, Iván Ezequiel Rodriguez wrote:
> Map hte_ts_get() -ENODEV to -EOPNOTSUPP so userspace sees the same
> errno as when CONFIG_HTE is disabled or EVENT_CLOCK_HTE is unsupported.
> 
> 

Makes sense. I hope it will not break any user-space users, though that's
highly unlikely.

[1/1] gpio: cdev: return EOPNOTSUPP when HTE is unavailable
      https://git.kernel.org/brgl/c/cf176c115497bc6462391c3118bedfd212092c4d

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>