I found the root cause: I did not read the data in my callback function! Note that an event source set to SD_EVENT_ON will fire continuously unless data is read from or written to the file descriptor to reset the mask of events seen.
2017-08-23 17:21 GMT-07:00 Yong Li <sdliy...@gmail.com>: > Hi all, > > I want to use the sd_event_add_io API to monitor a GPIO pin status > change. This pin supports intrrupts(echo both > edge). And it works > using the epoll code at https://gist.github.com/jadonk/2587524: The > callback function will be called if there is data change on the pin. > > However, the sd_event_add_io does not work: the callback will always > be triggered(without pin status change). I am using this example: > http://0pointer.net/blog/introducing-sd-event.html. Just replace the > fd = open("/sys/class/gpio/gpio34/value", O_RDWR | O_NONBLOCK); and > replace EPOLLIN using EPOLLPRI. > > Any suggestions/comments? > > > Thanks, > Yong _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
