Merge branch 'spi-4.20' into spi-linus

drivers/spi/spi-bcm2835.c

@@ -88,7 +88,7 @@ struct bcm2835_spi {
 	u8 *rx_buf;
 	int tx_len;
 	int rx_len;
-	bool dma_pending;
+	unsigned int dma_pending;
 };
 
 static inline u32 bcm2835_rd(struct bcm2835_spi *bs, unsigned reg)
@@ -155,8 +155,7 @@ static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
 	/* Write as many bytes as possible to FIFO */
 	bcm2835_wr_fifo(bs);
 
-	/* based on flags decide if we can finish the transfer */
-	if (bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_DONE) {
+	if (!bs->rx_len) {
 		/* Transfer complete - reset SPI HW */
 		bcm2835_spi_reset_hw(master);
 		/* wake up the framework */
@@ -233,10 +232,9 @@ static void bcm2835_spi_dma_done(void *data)
 	 * is called the tx-dma must have finished - can't get to this
 	 * situation otherwise...
 	 */
-	dmaengine_terminate_all(master->dma_tx);
-
-	/* mark as no longer pending */
-	bs->dma_pending = 0;
+	if (cmpxchg(&bs->dma_pending, true, false)) {
+		dmaengine_terminate_all(master->dma_tx);
+	}
 
 	/* and mark as completed */;
 	complete(&master->xfer_completion);
@@ -342,6 +340,7 @@ 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;
 	}
@@ -617,10 +616,9 @@ static void bcm2835_spi_handle_err(struct spi_master *master,
 	struct bcm2835_spi *bs = spi_master_get_devdata(master);
 
 	/* if an error occurred and we have an active dma, then terminate */
-	if (bs->dma_pending) {
+	if (cmpxchg(&bs->dma_pending, true, false)) {
 		dmaengine_terminate_all(master->dma_tx);
 		dmaengine_terminate_all(master->dma_rx);
-		bs->dma_pending = 0;
 	}
 	/* and reset */
 	bcm2835_spi_reset_hw(master);