davinci: edma: clear events in edma_start()
This patch fixes an issue where a DMA channel can erroneously process an
event generated by a previous transfer. A failure case is where DMA is
being used for SPI transmit and receive channels on OMAP L138. In this
case there is a single bit that controls all event generation from the
SPI peripheral. Therefore it is possible that between when edma_stop()
has been called for the transmit channel on a previous transfer and
edma_start() is called for the transmit channel on a subsequent transfer,
that a transmit event has been generated.
The fix is to clear events in edma_start(). This prevents false events
from being processed when events are enabled for that channel.
Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
1 file changed