Re: [PATCH v5 05/17] dmaengine: sh: rz-dmac: Add helper to compute the lmdesc address

[Frank Li]

On Tue, May 12, 2026 at 03:12:06PM +0300, Claudiu Beznea wrote:
> Add a helper function to compute the lmdesc address. This makes the
> code easier to understand, and the helper will be used in subsequent
> patches.


Add a helper function rz_dmac_lmdesc_addr() to compute the lmdesc address
to make code easier to understand, and ...

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>
> Changes in v5:
> - none
>
> Changes in v4:
> - none
>
> Changes in v3:
> - none, this patch is new
>
>  drivers/dma/sh/rz-dmac.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
> index 40ddf534c094..c48858b68dee 100644
> --- a/drivers/dma/sh/rz-dmac.c
> +++ b/drivers/dma/sh/rz-dmac.c
> @@ -259,6 +259,12 @@ static void rz_lmdesc_setup(struct rz_dmac_chan *channel,
>   * Descriptors preparation
>   */
>
> +static u32 rz_dmac_lmdesc_addr(struct rz_dmac_chan *channel, struct rz_lmdesc *lmdesc)
> +{
> +	return channel->lmdesc.base_dma +
> +	       (sizeof(struct rz_lmdesc) * (lmdesc - channel->lmdesc.base));
> +}
> +
>  static void rz_dmac_lmdesc_recycle(struct rz_dmac_chan *channel)
>  {
>  	struct rz_lmdesc *lmdesc = channel->lmdesc.head;
> @@ -284,9 +290,7 @@ static void rz_dmac_enable_hw(struct rz_dmac_chan *channel)
>
>  	rz_dmac_lmdesc_recycle(channel);
>
> -	nxla = channel->lmdesc.base_dma +
> -		(sizeof(struct rz_lmdesc) * (channel->lmdesc.head -
> -					     channel->lmdesc.base));
> +	nxla = rz_dmac_lmdesc_addr(channel, channel->lmdesc.head);
>
>  	chstat = rz_dmac_ch_readl(channel, CHSTAT, 1);
>  	if (!(chstat & CHSTAT_EN)) {
> --
> 2.43.0
>