Re: [PATCH v4 4/6] drm/msm/dsi: Use MSM and DRM DSC helper methods

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On 05/04/2023 03:41, Jessica Zhang wrote:
> Use MSM and DRM DSC helper methods to configure DSC for DSI.
>
> Changes in V2:
> - *_calculate_initial_scale_value --> *_set_initial_scale_value
> - Split pkt_per_line and eol_byte_num changes to a separate patch
> - Moved pclk_per_line calculation to hdisplay adjustment in `if (dsc)`
>    block of dsi_update_dsc_timing()
>
> Changes in v3:
> - Split pclk_per_intf calculation into a separate patch
> - Added slice_width check to dsi_timing_setup
> - Used MSM DSC helper to calculate total_bytes_per_intf
>
> Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/dsi/dsi_host.c | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 74d38f90398a..6a6218a9655f 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -28,6 +28,7 @@
>   #include "dsi.xml.h"
>   #include "sfpb.xml.h"
>   #include "dsi_cfg.h"
> +#include "msm_dsc_helper.h"
>   #include "msm_kms.h"
>   #include "msm_gem.h"
>   #include "phy/dsi_phy.h"
> @@ -848,7 +849,7 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>   	/* first calculate dsc parameters and then program
>   	 * compress mode registers
>   	 */
> -	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
> +	slice_per_intf = msm_dsc_get_slice_per_intf(dsc, hdisplay);
>   
>   	/*
>   	 * If slice_count is greater than slice_per_intf
> @@ -858,7 +859,7 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>   	if (dsc->slice_count > slice_per_intf)
>   		dsc->slice_count = 1;
>   
> -	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
> +	total_bytes_per_intf = msm_dsc_get_bytes_per_intf(dsc, hdisplay);
>   
>   	eol_byte_num = total_bytes_per_intf % 3;
>   	pkt_per_line = slice_per_intf / dsc->slice_count;
> @@ -936,6 +937,12 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>   			return;
>   		}
>   
> +		if (!dsc->slice_width || (mode->hdisplay < dsc->slice_width)) {
> +			pr_err("DSI: invalid slice width %d (pic_width: %d)\n",
> +			       dsc->slice_width, mode->hdisplay);
> +			return;
> +		}

This is not the "use of MSM and DRM DSC helper methods" and thus should 
be moved to a separate patch.

> +
>   		dsc->pic_width = mode->hdisplay;
>   		dsc->pic_height = mode->vdisplay;
>   		DBG("Mode %dx%d\n", dsc->pic_width, dsc->pic_height);
> @@ -1759,7 +1766,7 @@ static int dsi_populate_dsc_params(struct msm_dsi_host *msm_host, struct drm_dsc
>   		return ret;
>   	}
>   
> -	dsc->initial_scale_value = 32;
> +	drm_dsc_set_initial_scale_value(dsc);
>   	dsc->line_buf_depth = dsc->bits_per_component + 1;
>   
>   	return drm_dsc_compute_rc_parameters(dsc);

--
With best wishes
Dmitry