Re: [PATCH v3 33/34] dmaengine: qcom-gpi: defer callbacks via vchan

[Frank Li]

On Mon, Aug 10, 2026 at 11:09:34AM -0700, Allen Pais wrote:
> Complete descriptors through virt-dma instead of invoking callbacks
> directly from event processing. This preserves the transfer result for
> the shared vchan BH, which invokes the callback and frees the descriptor;
> drain that BH before releasing channel resources.
>
> Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx>
> ---

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


>  drivers/dma/qcom/gpi.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
> index a5055a6273af..2bc3a07ef092 100644
> --- a/drivers/dma/qcom/gpi.c
> +++ b/drivers/dma/qcom/gpi.c
> @@ -981,8 +981,12 @@ static void gpi_process_imed_data_event(struct gchan *gchan,
>  		result.result = DMA_TRANS_NOERROR;
>  	result.residue = gpi_desc->len - imed_event->length;
>
> -	dma_cookie_complete(&vd->tx);
> -	dmaengine_desc_get_callback_invoke(&vd->tx, &result);
> +	spin_lock_irqsave(&gchan->vc.lock, flags);
> +	list_del(&vd->node);
> +	vd->tx_result = result;
> +	vchan_cookie_complete(vd);
> +	spin_unlock_irqrestore(&gchan->vc.lock, flags);
> +	return;
>
>  gpi_free_desc:
>  	spin_lock_irqsave(&gchan->vc.lock, flags);
> @@ -1060,8 +1064,12 @@ static void gpi_process_xfer_compl_event(struct gchan *gchan,
>  	result.residue = gpi_desc->len - compl_event->length;
>  	dev_dbg(gpii->gpi_dev->dev, "Residue %d\n", result.residue);
>
> -	dma_cookie_complete(&vd->tx);
> -	dmaengine_desc_get_callback_invoke(&vd->tx, &result);
> +	spin_lock_irqsave(&gchan->vc.lock, flags);
> +	list_del(&vd->node);
> +	vd->tx_result = result;
> +	vchan_cookie_complete(vd);
> +	spin_unlock_irqrestore(&gchan->vc.lock, flags);
> +	return;
>
>  gpi_free_desc:
>  	spin_lock_irqsave(&gchan->vc.lock, flags);
> @@ -2009,6 +2017,7 @@ static void gpi_free_chan_resources(struct dma_chan *chan)
>
>  	/* free all allocated memory */
>  	gpi_free_ring(&gchan->ch_ring, gpii);
> +	dmaengine_kill_bh(&gchan->vc.chan);
>  	vchan_free_chan_resources(&gchan->vc);
>  	kfree(gchan->config);
>
> --
> 2.43.0
>