@@ -635,17 +635,17 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
slave_config.dst_maxburst = 1;
slave_config.device_fc = false;
- dma->chan_tx = dma_request_slave_channel(dev->dev, "tx");
- if (!dma->chan_tx) {
- dev_err(dev->dev, "can't get a DMA channel for tx\n");
- ret = -EBUSY;
+ dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx");
+ if (IS_ERR(dma->chan_tx)) {
+ ret = PTR_ERR(dma->chan_tx);
+ dma->chan_tx = NULL;
goto error;
}
- dma->chan_rx = dma_request_slave_channel(dev->dev, "rx");
- if (!dma->chan_rx) {
- dev_err(dev->dev, "can't get a DMA channel for rx\n");
- ret = -EBUSY;
+ dma->chan_rx = dma_request_slave_channel_reason(dev->dev, "rx");
+ if (IS_ERR(dma->chan_rx)) {
+ ret = PTR_ERR(dma->chan_rx);
+ dma->chan_rx = NULL;
goto error;
}
@@ -666,6 +666,7 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
sg_init_table(&dma->sg, 1);
dma->buf_mapped = false;
dma->xfer_in_progress = false;
+ dev->use_dma = true;
dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n",
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
@@ -673,7 +674,8 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
return ret;
error:
- dev_info(dev->dev, "can't use DMA\n");
+ if (ret != -EPROBE_DEFER)
+ dev_info(dev->dev, "can't use DMA, error %d\n", ret);
if (dma->chan_rx)
dma_release_channel(dma->chan_rx);
if (dma->chan_tx)
@@ -742,8 +744,9 @@ static int at91_twi_probe(struct platform_device *pdev)
clk_prepare_enable(dev->clk);
if (dev->dev->of_node) {
- if (at91_twi_configure_dma(dev, phy_addr) == 0)
- dev->use_dma = true;
+ rc = at91_twi_configure_dma(dev, phy_addr);
+ if (rc == -EPROBE_DEFER)
+ return rc;
}
rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
If dma controller is not probed, defer i2c probe. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> --- Arnd, It's a combination of the first patch I sent and yours. As you said that my patch "looks wrong but actually it's ok" I didn't dare to add your signed-off-by. drivers/i2c/busses/i2c-at91.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)