Re: [PATCH v2 3/4] dmaengine: pl330: Store pointer to slave device

Krzysztof Kozlowski
2017-01-09T18:08:21Z

On Mon, Jan 9, 2017 at 4:03 PM, Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
> Store the pointer to slave device, which requested our channel. It will be
> later used to implement runtime PM of PL330 DMA controller. Although
> DMA channels might be requested many times, each DMA peripheral channel is
> physically dedicated only for specific hardware, so there should be only
> one slave device for each channel.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> drivers/dma/pl330.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 3c80e71271a2..9c72f535739c 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -450,6 +450,7 @@ struct dma_pl330_chan {
>
> /* for runtime pm tracking */
> bool active;
> + struct device *slave;
> };
>
> struct pl330_dmac {
> @@ -2113,6 +2114,14 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,
> if (chan_id >= pl330->num_peripherals)
> return NULL;
>
> + if (!pl330->peripherals[chan_id].slave)
> + pl330->peripherals[chan_id].slave = slave;

Following coding style, this should be inside {} because the other
branch has them. Beside that:
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof

> + else if (pl330->peripherals[chan_id].slave != slave) {
> + dev_err(pl330->ddma.dev,
> + "Can't use same channel with multiple slave devices!\n");
> + return NULL;
> + }
> +
> return dma_get_slave_channel(&pl330->peripherals[chan_id].chan);
> }
>
> --
> 1.9.1
>