Re: [PATCH] dmaengine: sh: rz-dmac: Fix rz_dmac_terminate_all()

[Claudiu Beznea]

On 11/6/25 14:52, Biju Das wrote:
> After audio full duplex testing, playing the recorded file contains a few
> playback frames for the first time. The rz_dmac_terminate_all() does not
> reset all the hardware descriptors queued previously, leading to the wrong
> descriptor being picked up during the next DMA transfer. Fix this issue by
> resetting all descriptor headers for a channel in rz_dmac_terminate_all()
> as rz_dmac_lmdesc_recycle() points to the proper descriptor header filled
> by the rz_dmac_prepare_descs_for_slave_sg().
> 
> Cc: stable@xxxxxxxxxx
> Fixes: 5000d37042a6 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>

> ---
>  drivers/dma/sh/rz-dmac.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
> index 1f687b08d6b8..3087bbd11d59 100644
> --- a/drivers/dma/sh/rz-dmac.c
> +++ b/drivers/dma/sh/rz-dmac.c
> @@ -557,11 +557,16 @@ rz_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>  static int rz_dmac_terminate_all(struct dma_chan *chan)
>  {
>  	struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
> +	struct rz_lmdesc *lmdesc = channel->lmdesc.base;
>  	unsigned long flags;
> +	unsigned int i;
>  	LIST_HEAD(head);
>  
>  	rz_dmac_disable_hw(channel);
>  	spin_lock_irqsave(&channel->vc.lock, flags);
> +	for (i = 0; i < DMAC_NR_LMDESC; i++)
> +		lmdesc[i].header = 0;
> +
>  	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
>  	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
>  	vchan_get_all_descriptors(&channel->vc, &head);