dmaengine: xilinx_dma: Configure parking registers only if parking enabled

The VDMA can work in two modes, parking or circular. Do not program the
parking mode registers in case circular mode is used, it is useless.

Signed-off-by: Marek Vasut <[email protected]>
Reviewed-by: Radhey Shyam Pandey <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: Marek Vasut

drivers/dma/xilinx/xilinx_dma.c

@@ -1404,16 +1404,18 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
 
 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
 
-	j = chan->desc_submitcount;
-	reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
-	if (chan->direction == DMA_MEM_TO_DEV) {
-		reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
-		reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
-	} else {
-		reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
-		reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
+	if (config->park) {
+		j = chan->desc_submitcount;
+		reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
+		if (chan->direction == DMA_MEM_TO_DEV) {
+			reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
+			reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
+		} else {
+			reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
+			reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
+		}
+		dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
 	}
-	dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
 
 	/* Start the hardware */
 	xilinx_dma_start(chan);