1 files changed, 33 insertions, 4 deletions

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index 189b517f77fc..1cf9e3ffe07b 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -36,6 +36,31 @@ static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
 	return true;
 }
 
+static void mid_spi_maxburst_init(struct dw_spi *dws)
+{
+	struct dma_slave_caps caps;
+	u32 max_burst, def_burst;
+	int ret;
+
+	def_burst = dws->fifo_len / 2;
+
+	ret = dma_get_slave_caps(dws->rxchan, &caps);
+	if (!ret && caps.max_burst)
+		max_burst = caps.max_burst;
+	else
+		max_burst = RX_BURST_LEVEL;
+
+	dws->rxburst = min(max_burst, def_burst);
+
+	ret = dma_get_slave_caps(dws->txchan, &caps);
+	if (!ret && caps.max_burst)
+		max_burst = caps.max_burst;
+	else
+		max_burst = TX_BURST_LEVEL;
+
+	dws->txburst = min(max_burst, def_burst);
+}
+
 static int mid_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws)
 {
 	struct dw_dma_slave slave = {
@@ -73,6 +98,8 @@ static int mid_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws)
 
 	init_completion(&dws->dma_completion);
 
+	mid_spi_maxburst_init(dws);
+
 	return 0;
 
 free_rxchan:
@@ -100,6 +127,8 @@ static int mid_spi_dma_init_generic(struct device *dev, struct dw_spi *dws)
 
 	init_completion(&dws->dma_completion);
 
+	mid_spi_maxburst_init(dws);
+
 	return 0;
 }
 
@@ -229,7 +258,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
 	memset(&txconf, 0, sizeof(txconf));
 	txconf.direction = DMA_MEM_TO_DEV;
 	txconf.dst_addr = dws->dma_addr;
-	txconf.dst_maxburst = TX_BURST_LEVEL;
+	txconf.dst_maxburst = dws->txburst;
 	txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	txconf.dst_addr_width = convert_dma_width(dws->n_bytes);
 	txconf.device_fc = false;
@@ -321,7 +350,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
 	memset(&rxconf, 0, sizeof(rxconf));
 	rxconf.direction = DMA_DEV_TO_MEM;
 	rxconf.src_addr = dws->dma_addr;
-	rxconf.src_maxburst = RX_BURST_LEVEL;
+	rxconf.src_maxburst = dws->rxburst;
 	rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	rxconf.src_addr_width = convert_dma_width(dws->n_bytes);
 	rxconf.device_fc = false;
@@ -346,8 +375,8 @@ static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 {
 	u16 imr = 0, dma_ctrl = 0;
 
-	dw_writel(dws, DW_SPI_DMARDLR, RX_BURST_LEVEL - 1);
-	dw_writel(dws, DW_SPI_DMATDLR, TX_BURST_LEVEL);
+	dw_writel(dws, DW_SPI_DMARDLR, dws->rxburst - 1);
+	dw_writel(dws, DW_SPI_DMATDLR, dws->fifo_len - dws->txburst);
 
 	if (xfer->tx_buf) {
 		dma_ctrl |= SPI_DMA_TDMAE;