Re: [PATCH v3 1/2] dma: imx-dma: Add oftree support

[Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>]

On Monday 25 February 2013, Markus Pargmann wrote:
> Adding devicetree support for imx-dma driver. Use driver name for
> function 'imx_dma_is_general_purpose' because the devicename for
> devicetree initialized devices is different.
> 
> Changes in V3:
> - Create a imxdma translate function to pass the device object into the
>   filter function.
> 
> Changes in V2:
> - Change the driver to use generic DMA DT bindings.
> - Add a imx-dma filter function that sets the dma request line in
>   private data.
> 
> Signed-off-by: Markus Pargmann <mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Cc: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>

Looks correct now,

Reviewed-by: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>

I have one idea for an optimization though:

> +static bool imxdma_filter_fn(struct dma_chan *chan, void *param)
> +{
> +	struct imxdma_filter_data *fdata = param;
> +	struct imx_dma_data *data;
> +
> +	if (chan->device->dev != fdata->imxdma->dev)
> +		return false;
> +
> +	data = kzalloc(sizeof(*data), GFP_KERNEL);
> +
> +	if (!data)
> +		return false;
> +
> +	data->dma_request = fdata->request;
> +	data->alloc_ctl_filter = true;
> +	chan->private = data;
> +
> +	return true;
> +}

There is already a "dma_request" member in "struct imxdma_channel", so
you could use that instead of allocating the imx_dma_data here.

Then you don't need to keep track of freeing that memory again, but
you might have to change a few other functions that look at data->dma_request
rather than chan->dma_request at the moment and change them to
use the latter instead. You can copy data->dma_request over in the
alloc_chan_resources functions for the legacy case.

	Arnd