[PATCH v2 0/6] gpio: notify user-space about config changes in the kernel

Bartosz Golaszewski
2024-10-10T09:10:34Z

We currently only emit events on changed line config to user-space on
changes made from user-space. Users have no way of getting notified
about in-kernel changes. This series improves the situation and also
contains a couple other related improvements.

This is a reworked approach which gets and stores as much info (all of
it actually, except for the pinctrl state) the moment the event occurrs
but moves the actual queueing of the event on the kfifo to a dedicated
high-priority, ordered workqueue.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
Changes in v2:
- put all line-info events emitting on a workqueue to allow queueing
them from atomic context
- switch the notifier type used for emitting info events to atomic
- add a patch notifying user-space about drivers requesting their own
descs
- drop patches that were picked up
- Link to v1: https://lore.kernel.org/r/20241004-gpio-notify-in-kernel-events-v1-0-8ac29e1df4fe@linaro.org

---
Bartosz Golaszewski (6):
gpiolib: notify user-space when a driver requests its own desc
gpio: cdev: prepare gpio_desc_to_lineinfo() for being called from atomic
gpiolib: add a per-gpio_device line state notification workqueue
gpio: cdev: put emitting the line state events on a workqueue
gpiolib: switch the line state notifier to atomic
gpiolib: notify user-space about in-kernel line state changes

drivers/gpio/gpiolib-cdev.c | 126 +++++++++++++++++++++++++++++++++-----------
drivers/gpio/gpiolib.c | 79 +++++++++++++++++++++++----
drivers/gpio/gpiolib.h | 8 ++-
3 files changed, 171 insertions(+), 42 deletions(-)
---
base-commit: b7adfb6076ff0c1ebbde56d1903daa3d07db92c5
change-id: 20240924-gpio-notify-in-kernel-events-07cd912153e8

Best regards,
--
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>