Re: [PATCH v1 4/4] dmaengine: Unify checks in dma_request_chan()

[Frank Li]

On Mon, Oct 07, 2024 at 06:06:48PM +0300, Andy Shevchenko wrote:
> Use firmware node and unify checks accordingly in dma_request_chan().
> As a side effect we get rid of the node dereferencing in struct device.

suggest:

Use dev_fwnode() to simple check logic for device tree and ACPI in
dma_request_chan().

Frank

>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
>  drivers/dma/dmaengine.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index dd4224d90f07..758fcd0546d8 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -40,6 +40,8 @@
>  #include <linux/dmaengine.h>
>  #include <linux/hardirq.h>
>  #include <linux/spinlock.h>
> +#include <linux/of.h>
> +#include <linux/property.h>
>  #include <linux/percpu.h>
>  #include <linux/rcupdate.h>
>  #include <linux/mutex.h>
> @@ -812,15 +814,13 @@ static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
>   */
>  struct dma_chan *dma_request_chan(struct device *dev, const char *name)
>  {
> +	struct fwnode_handle *fwnode = dev_fwnode(dev);
>  	struct dma_device *d, *_d;
>  	struct dma_chan *chan = NULL;
>
> -	/* If device-tree is present get slave info from here */
> -	if (dev->of_node)
> -		chan = of_dma_request_slave_channel(dev->of_node, name);
> -
> -	/* If device was enumerated by ACPI get slave info from here */
> -	if (has_acpi_companion(dev) && !chan)
> +	if (is_of_node(fwnode))
> +		chan = of_dma_request_slave_channel(to_of_node(fwnode), name);
> +	else if (is_acpi_device_node(fwnode))
>  		chan = acpi_dma_request_slave_chan_by_name(dev, name);
>
>  	if (PTR_ERR(chan) == -EPROBE_DEFER)
> --
> 2.43.0.rc1.1336.g36b5255a03ac
>