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Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org> |
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| .. | ||
| accel | ||
| adc | ||
| amplifiers | ||
| common | ||
| dac | ||
| frequency | ||
| gyro | ||
| imu | ||
| light | ||
| magnetometer | ||
| pressure | ||
| temperature | ||
| trigger | ||
| buffer_cb.c | ||
| iio_core_trigger.h | ||
| iio_core.h | ||
| industrialio-buffer.c | ||
| industrialio-core.c | ||
| industrialio-event.c | ||
| industrialio-trigger.c | ||
| industrialio-triggered-buffer.c | ||
| inkern.c | ||
| Kconfig | ||
| kfifo_buf.c | ||
| Makefile | ||