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SubjectRe: [PATCH v4 1/2] i2c: add DMA support for freescale i2c driver
Date
On Friday, April 04, 2014 at 04:41:11 AM, Yuan Yao wrote:
> Add dma support for i2c. This function depend on DMA driver.
> You can turn on it by write both the dmas and dma-name properties in dts
> node.
>
> Signed-off-by: Yuan Yao <yao.yuan@freescale.com>

[...]

Since you will be fixing that superfluous return 0; (I actually wonder, did you
really test the driver at all before submitting it?) ...

> +static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
> + struct i2c_msg *msgs)
> +{
> + struct imx_i2c_dma *dma = i2c_imx->dma;
> + struct dma_async_tx_descriptor *txdesc;
> + struct device *dev = &i2c_imx->adapter.dev;
> +
> + dma->dma_buf = dma_map_single(dma->chan_using->device->dev, msgs->buf,

Please fix this "noodle" here too, the chain of pointers is quite long, you can
just define a variable for that.

> + dma->dma_len, dma->dma_data_dir);
> + if (dma_mapping_error(dma->chan_using->device->dev, dma->dma_buf)) {
> + dev_err(dev, "DMA mapping failed\n");
> + return -EINVAL;
> + }
> +
> + txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
> + dma->dma_len, dma->dma_transfer_dir,
> + DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> + if (!txdesc) {
> + dev_err(dev, "Not able to get desc for DMA xfer\n");
> + dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
> + dma->dma_len, dma->dma_data_dir);
> + return -EINVAL;
> + }
> +
> + txdesc->callback = i2c_imx_dma_callback;
> + txdesc->callback_param = i2c_imx;
> + dmaengine_submit(txdesc);
> + dma_async_issue_pending(dma->chan_using);
> +
> + return 0;
> +}
[...]

Other than those two things,

Reviewed-by: Marek Vasut <marex@denx.de>


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