Re: [PATCH v4 1/4] dmaengine: add dma_device_get() helper

On Tue, Aug 18, 2026 at 03:43:45AM +0000, Shivank Garg wrote:
> Add dma_device_get() helper to match dma_device_put() to make code
> symmetric. It wraps open-coded kref_get_unless_zero() and asserts that
> dma_list_mutex is held, matching its put counterpart.
>
> No functional change intended.
>
> Suggested-by: Frank Li <[email protected]>
> Signed-off-by: Shivank Garg <[email protected]>
> ---
>  drivers/dma/dmaengine.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index 6ffd8bd82154..77638dc16e71 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -433,6 +433,12 @@ static void dma_device_release(struct kref *ref)
>  		device->device_release(device);
>  }
>
> +static bool dma_device_get(struct dma_device *device)

Please the same return type of kref_get_unless_zero(),

it should be int.

Frank

> +{
> +	lockdep_assert_held(&dma_list_mutex);
> +	return kref_get_unless_zero(&device->ref);
> +}
> +
>  static void dma_device_put(struct dma_device *device)
>  {
>  	lockdep_assert_held(&dma_list_mutex);
> @@ -460,8 +466,7 @@ static int dma_chan_get(struct dma_chan *chan)
>  	if (!try_module_get(owner))
>  		return -ENODEV;
>
> -	ret = kref_get_unless_zero(&chan->device->ref);
> -	if (!ret) {
> +	if (!dma_device_get(chan->device)) {
>  		ret = -ENODEV;
>  		goto module_put_out;
>  	}
>
> --
> 2.43.0
>