[PATCH] dmaengine: xilinx_dma: Configure parking registers only if parking enabled

[Pandey, Radhey Shyam]

> -----Original Message-----
> From: Marek Vasut <marex at denx.de>
> Sent: Thursday, October 31, 2024 10:41 PM
> To: dmaengine at vger.kernel.org
> Cc: Marek Vasut <marex at denx.de>; Uwe Kleine-König <u.kleine-
> koenig at baylibre.com>; Simek, Michal <michal.simek at amd.com>; Peter Korsgaard
> <peter at korsgaard.com>; Pandey, Radhey Shyam
> <radhey.shyam.pandey at amd.com>; Vinod Koul <vkoul at kernel.org>; linux-arm-
> kernel at lists.infradead.org
> Subject: [PATCH] dmaengine: xilinx_dma: Configure parking registers only if parking
> enabled
> 
> The VDMA can work in two modes, parking or circular. Do not program the parking
> mode registers in case circular mode is used, it is useless.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>

Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey at amd.com>
Thanks!
> ---
> Cc: "Uwe Kleine-König" <u.kleine-koenig at baylibre.com>
> Cc: Michal Simek <michal.simek at amd.com>
> Cc: Peter Korsgaard <peter at korsgaard.com>
> Cc: Radhey Shyam Pandey <radhey.shyam.pandey at amd.com>
> Cc: Vinod Koul <vkoul at kernel.org>
> Cc: dmaengine at vger.kernel.org
> Cc: linux-arm-kernel at lists.infradead.org
> ---
>  drivers/dma/xilinx/xilinx_dma.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index
> 48647c8a64a5b..87db381ff1286 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -1404,16 +1404,18 @@ static void xilinx_vdma_start_transfer(struct
> xilinx_dma_chan *chan)
> 
>  	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
> 
> -	j = chan->desc_submitcount;
> -	reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
> -	if (chan->direction == DMA_MEM_TO_DEV) {
> -		reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
> -		reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
> -	} else {
> -		reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
> -		reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
> +	if (config->park) {
> +		j = chan->desc_submitcount;
> +		reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
> +		if (chan->direction == DMA_MEM_TO_DEV) {
> +			reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
> +			reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
> +		} else {
> +			reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
> +			reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
> +		}
> +		dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
>  	}
> -	dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
> 
>  	/* Start the hardware */
>  	xilinx_dma_start(chan);
> --
> 2.45.2