Re: [RFC PATCH 2/2] drm/msm/dsi: use new dpu_dsc_populate_dsc_config()

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 24/02/2023 21:40, Kuogee Hsieh wrote:
> use new introduced dpu_dsc_populate_dsc_config() to calculate
> and populate drm_dsc_info instead of hard code value.

DPU is an optional component, so DSI driver should not depend on the DPU 
driver.

> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 78 ++++++--------------------------------
>   1 file changed, 12 insertions(+), 66 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 31ad193..5f3f84f 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0-only
>   /*
>    * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2023. Qualcomm Innovation Center, Inc. All rights reserved
>    */
>   
>   #include <linux/clk.h>
> @@ -21,7 +22,6 @@
>   
>   #include <video/mipi_display.h>
>   
> -#include <drm/display/drm_dsc_helper.h>
>   #include <drm/drm_of.h>
>   
>   #include "dsi.h"
> @@ -31,6 +31,7 @@
>   #include "msm_kms.h"
>   #include "msm_gem.h"
>   #include "phy/dsi_phy.h"
> +#include "dpu_dsc_helper.h"
>   
>   #define DSI_RESET_TOGGLE_DELAY_MS 20
>   
> @@ -1819,29 +1820,8 @@ static int dsi_host_parse_lane_data(struct msm_dsi_host *msm_host,
>   	return -EINVAL;
>   }
>   
> -static u32 dsi_dsc_rc_buf_thresh[DSC_NUM_BUF_RANGES - 1] = {
> -	0x0e, 0x1c, 0x2a, 0x38, 0x46, 0x54, 0x62,
> -	0x69, 0x70, 0x77, 0x79, 0x7b, 0x7d, 0x7e
> -};
> -
> -/* only 8bpc, 8bpp added */
> -static char min_qp[DSC_NUM_BUF_RANGES] = {
> -	0, 0, 1, 1, 3, 3, 3, 3, 3, 3, 5, 5, 5, 7, 13
> -};
> -
> -static char max_qp[DSC_NUM_BUF_RANGES] = {
> -	4, 4, 5, 6, 7, 7, 7, 8, 9, 10, 11, 12, 13, 13, 15
> -};
> -
> -static char bpg_offset[DSC_NUM_BUF_RANGES] = {
> -	2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
> -};
> -
>   static int dsi_populate_dsc_params(struct msm_dsi_host *msm_host, struct drm_dsc_config *dsc)
>   {
> -	int i;
> -	u16 bpp = dsc->bits_per_pixel >> 4;
> -
>   	if (dsc->bits_per_pixel & 0xf) {
>   		DRM_DEV_ERROR(&msm_host->pdev->dev, "DSI does not support fractional bits_per_pixel\n");
>   		return -EINVAL;
> @@ -1852,50 +1832,16 @@ static int dsi_populate_dsc_params(struct msm_dsi_host *msm_host, struct drm_dsc
>   		return -EOPNOTSUPP;
>   	}
>   
> -	dsc->rc_model_size = 8192;
> -	dsc->first_line_bpg_offset = 12;
> -	dsc->rc_edge_factor = 6;
> -	dsc->rc_tgt_offset_high = 3;
> -	dsc->rc_tgt_offset_low = 3;
> -	dsc->simple_422 = 0;
> -	dsc->convert_rgb = 1;
> -	dsc->vbr_enable = 0;
> -
> -	/* handle only bpp = bpc = 8 */
> -	for (i = 0; i < DSC_NUM_BUF_RANGES - 1 ; i++)
> -		dsc->rc_buf_thresh[i] = dsi_dsc_rc_buf_thresh[i];
> -
> -	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
> -		dsc->rc_range_params[i].range_min_qp = min_qp[i];
> -		dsc->rc_range_params[i].range_max_qp = max_qp[i];
> -		/*
> -		 * Range BPG Offset contains two's-complement signed values that fill
> -		 * 8 bits, yet the registers and DCS PPS field are only 6 bits wide.
> -		 */
> -		dsc->rc_range_params[i].range_bpg_offset = bpg_offset[i] & DSC_RANGE_BPG_OFFSET_MASK;
> -	}
> -
> -	dsc->initial_offset = 6144;		/* Not bpp 12 */
> -	if (bpp != 8)
> -		dsc->initial_offset = 2048;	/* bpp = 12 */
> -
> -	if (dsc->bits_per_component <= 10)
> -		dsc->mux_word_size = DSC_MUX_WORD_SIZE_8_10_BPC;
> -	else
> -		dsc->mux_word_size = DSC_MUX_WORD_SIZE_12_BPC;
> -
> -	dsc->initial_xmit_delay = 512;
> -	dsc->initial_scale_value = 32;
> -	dsc->first_line_bpg_offset = 12;
> -	dsc->line_buf_depth = dsc->bits_per_component + 1;
> -
> -	/* bpc 8 */
> -	dsc->flatness_min_qp = 3;
> -	dsc->flatness_max_qp = 12;
> -	dsc->rc_quant_incr_limit0 = 11;
> -	dsc->rc_quant_incr_limit1 = 11;
> -
> -	return drm_dsc_compute_rc_parameters(dsc);
> +	/*
> +	 * NOTE:
> +	 * dsc->dsc_version_major, dsc->dsc_version_minor
> +	 * dsc->bits_per_pixel,
> +	 * dsc->bits_per_component,
> +	 * dsc->native_422, dsc->native_420
> +	 *
> +	 * above parameters must be populated

Comments
In Yoda style
written should be not.

> +	 */
> +	return dpu_dsc_populate_dsc_config(dsc, 0);
>   }
>   
>   static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)

-- 
With best wishes
Dmitry