Re: [PATCH v6, 13/14] drm/mediatek: add fifo_size into rdma private data

[CK Hu]

Hi, Yongqiang:

On Thu, 2020-01-02 at 12:00 +0800, Yongqiang Niu wrote:
> the fifo size of rdma in mt8183 is different.
> rdma0 fifo size is 5k
> rdma1 fifo size is 2k
> 
> Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> index 405afef..691480b 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> @@ -62,6 +62,7 @@ struct mtk_disp_rdma {
>  	struct mtk_ddp_comp		ddp_comp;
>  	struct drm_crtc			*crtc;
>  	const struct mtk_disp_rdma_data	*data;
> +	u32				fifo_size;
>  };
>  
>  static inline struct mtk_disp_rdma *comp_to_rdma(struct mtk_ddp_comp *comp)
> @@ -130,10 +131,16 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width,
>  	unsigned int threshold;
>  	unsigned int reg;
>  	struct mtk_disp_rdma *rdma = comp_to_rdma(comp);
> +	u32 rdma_fifo_size;
>  
>  	rdma_update_bits(comp, DISP_REG_RDMA_SIZE_CON_0, 0xfff, width);
>  	rdma_update_bits(comp, DISP_REG_RDMA_SIZE_CON_1, 0xfffff, height);
>  
> +	if (rdma->fifo_size)
> +		rdma_fifo_size = rdma->fifo_size;
> +	else
> +		rdma_fifo_size = RDMA_FIFO_SIZE(rdma);
> +
>  	/*
>  	 * Enable FIFO underflow since DSI and DPI can't be blocked.
>  	 * Keep the FIFO pseudo size reset default of 8 KiB. Set the
> @@ -142,7 +149,7 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width,
>  	 */
>  	threshold = width * height * vrefresh * 4 * 7 / 1000000;
>  	reg = RDMA_FIFO_UNDERFLOW_EN |
> -	      RDMA_FIFO_PSEUDO_SIZE(RDMA_FIFO_SIZE(rdma)) |
> +	      RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) |
>  	      RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);
>  	writel(reg, comp->regs + DISP_REG_RDMA_FIFO_CON);
>  }
> @@ -284,6 +291,18 @@ static int mtk_disp_rdma_probe(struct platform_device *pdev)
>  		return comp_id;
>  	}
>  
> +	if (of_find_property(dev->of_node, "mediatek,rdma_fifo_size", &ret)) {

"mediatek,rdma_fifo_size" does not exists in binding document.

> +		ret = of_property_read_u32(dev->of_node,
> +					   "mediatek,rdma_fifo_size",
> +					   &priv->fifo_size);
> +		if (ret) {
> +			dev_err(dev, "Failed to get rdma fifo size\n");
> +			return ret;
> +		}
> +
> +		priv->fifo_size *= SZ_1K;

Why not define fifo_size in 'bytes' ?

Regards,
CK

> +	}
> +
>  	ret = mtk_ddp_comp_init(dev, dev->of_node, &priv->ddp_comp, comp_id,
>  				&mtk_disp_rdma_funcs);
>  	if (ret) {