On Thu, Jan 14, 2021 at 05:27:11PM -0800, Kevin Herbert wrote:

The loop sends either one or two events to the slave driver. If the
state is I2C_SLAVE_READ_REQUESTED, we synthesize the
I2C_SLAVE_READ_PROCESSED event, and then our state becomes
I2C_SLAVE_READ_PROCESSED. In all other states, we transition to
I2C_SLAVE_STOP and exit the loop.

It is not a busy loop at all. It is calling the callback handler (that
already expects to be in IRQ context) one or two times, and then it
exits the loop.

Oleksij, does this answer your question?