fix(i2c): Send repeated starts in byte-by-byte I2C transactions #782
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Summary
The
embedded_hal::i2c::I2cspecification mandates that a repeated start (instead of a stop+start) is sent between transactions of a different type (read/write) when usingI2c::transactionorI2c::read_write. Currently, the HAL, while it respects not sending a stop+start between two operations of the same type, does send stop+start between transactions of a different type.This PR fixes that behavior, and enables sending repeated starts between transactions of different types.
Unfortunately, in DMA mode, the hardware is only capable of sending stop+starts. If a user absolutely needs repeated starts, the only workaround is to use the I2C without DMA.
Checklist