- Align the RX buffers on the cache line size, otherwise the requirement
of partial cache line flushes on every are pretty much guaranteed. [1]
- Make the code setting the RX timeout match its comment (apparently,
start and stop bits were missed in the previous calculation). [1]
- Cover the busdma operations in at91_usart_bus_{ipend,transmit}() with
the hardware mutex, too, so these don't race against each other.
- In at91_usart_bus_ipend(), reduce duplication in the code dealing with
TX interrupts.
- In at91_usart_bus_ipend(), turn the code dealing with RX interrupts
into an else-if cascade in order reduce its complexity and to improve
its run-time behavior.
- In at91_usart_bus_ipend(), add missing BUS_DMASYNC_PREREAD calls on
the RX buffer map before handing things over to the hardware again. [1]
- In at91_usart_bus_getsig(), used a variable of sufficient width for
storing the contents of USART_CSR.
- Use KOBJMETHOD_END.
- Remove an unused header.
Submitted by: Ian Lepore [1]
Reviewed by: Ian Lepore
MFC after: 1 week
8a7eceb74a