[PATCH] i2c: layerscape: use PIO when fail to request dma channel

[Qiang Zhao]

When fail to request DMA TX/RX channel, use PIO instead for layerscape.

Signed-off-by: Zhao Qiang <qiang.z...@nxp.com>
---
 drivers/i2c/busses/i2c-imx.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 98b278613cf2..39a5ab4cf332 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -347,9 +347,13 @@ static int i2c_imx_dma_request(struct imx_i2c_struct 
*i2c_imx,
 
        dma->chan_tx = dma_request_chan(dev, "tx");
        if (IS_ERR(dma->chan_tx)) {
+#ifdef CONFIG_ARCH_LAYERSCAPE
+               dev_dbg(dev, "can't request DMA tx channel\n");
+#else
                ret = PTR_ERR(dma->chan_tx);
                if (ret != -ENODEV && ret != -EPROBE_DEFER)
                        dev_err(dev, "can't request DMA tx channel (%d)\n", 
ret);
+#endif
                goto fail_al;
        }
 
@@ -366,9 +370,13 @@ static int i2c_imx_dma_request(struct imx_i2c_struct 
*i2c_imx,
 
        dma->chan_rx = dma_request_chan(dev, "rx");
        if (IS_ERR(dma->chan_rx)) {
+#ifdef CONFIG_ARCH_LAYERSCAPE
+               dev_dbg(dev, "can't request DMA rx channel\n");
+#else
                ret = PTR_ERR(dma->chan_rx);
                if (ret != -ENODEV && ret != -EPROBE_DEFER)
                        dev_err(dev, "can't request DMA rx channel (%d)\n", 
ret);
+#endif
                goto fail_tx;
        }
 
@@ -396,6 +404,9 @@ static int i2c_imx_dma_request(struct imx_i2c_struct 
*i2c_imx,
        dma_release_channel(dma->chan_tx);
 fail_al:
        devm_kfree(dev, dma);
+#ifdef CONFIG_ARCH_LAYERSCAPE
+       dev_info(dev, "can't use DMA, using PIO instead.\n");
+#endif
        /* return successfully if there is no dma support */
        return ret == -ENODEV ? 0 : ret;
 }
-- 
2.17.1