[PATCH 2/7] spi: bcm2835: Fix book-keeping of DMA termination

[Lukas Wunner <lukas@xxxxxxxxx>]

If submission of a DMA TX transfer succeeds but submission of the
corresponding RX transfer does not, the BCM2835 SPI driver terminates
the TX transfer but neglects to reset the dma_pending flag to false.

Thus, if the next transfer uses interrupt mode (because it is shorter
than BCM2835_SPI_DMA_MIN_LENGTH) and runs into a timeout,
dmaengine_terminate_all() will be called both for TX (once more) and
for RX (which was never started in the first place).  Fix it.

Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Fixes: 3ecd37edaa2a ("spi: bcm2835: enable dma modes for transfers meeting certain conditions")
Cc: stable@xxxxxxxxxxxxxxx # v4.2+
Cc: Mathias Duckeck <m.duckeck@xxxxxxxxx>
Cc: Frank Pavlic <f.pavlic@xxxxxxxxx>
Cc: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Cc: Noralf Trønnes <noralf@xxxxxxxxxxx>
---
 drivers/spi/spi-bcm2835.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index fa7844a956c7..594e9712ecbc 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -341,6 +341,7 @@ static int bcm2835_spi_transfer_one_dma(struct spi_master *master,
 	if (ret) {
 		/* need to reset on errors */
 		dmaengine_terminate_all(master->dma_tx);
+		bs->dma_pending = false;
 		bcm2835_spi_reset_hw(master);
 		return ret;
 	}
-- 
2.19.1