Re: [PATCH v4 1/2] drm/msm/dpu: retrieve DSI DSC struct through priv->dsi[0]

[Dmitry Baryshkov]

On 21/06/2023 19:18, Kuogee Hsieh wrote:
> Currently DSI DSC struct is populated at display setup during
> system bootup. This mechanism works fine with embedded display
> but not for pluggable displays as the DSC struct will become
> stale once external display unplugged.
>
> Move storing of DSI DSC struct to both atomic_mode_set() and
> atomic_enable() so that same mechanism will work for both
> embedded display and pluggable displays.
>
> Changes in v4:
> -- fix checkpatch.pl warning
>
> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 30 +++++++++++++++++++++++++----
>   1 file changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 2e1873d..367d374 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -543,11 +543,24 @@ bool dpu_encoder_use_dsc_merge(struct drm_encoder *drm_enc)
>   	return (num_dsc > 0) && (num_dsc > intf_count);
>   }
>   
> +static struct drm_dsc_config *dpu_encoder_get_dsc_config(struct drm_encoder *drm_enc)
> +{
> +	struct msm_drm_private *priv = drm_enc->dev->dev_private;
> +	struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> +	int index = dpu_enc->disp_info.h_tile_instance[0];
> +
> +	if (dpu_enc->disp_info.intf_type == INTF_DSI)
> +		return msm_dsi_get_dsc_config(priv->dsi[index]);
> +
> +	return NULL;
> +}
> +
>   static struct msm_display_topology dpu_encoder_get_topology(
>   			struct dpu_encoder_virt *dpu_enc,
>   			struct dpu_kms *dpu_kms,
>   			struct drm_display_mode *mode,
> -			struct drm_crtc_state *crtc_state)
> +			struct drm_crtc_state *crtc_state,
> +			struct drm_dsc_config *dsc)
>   {
>   	struct msm_display_topology topology = {0};
>   	int i, intf_count = 0;
> @@ -579,7 +592,7 @@ static struct msm_display_topology dpu_encoder_get_topology(
>   
>   	topology.num_intf = intf_count;
>   
> -	if (dpu_enc->dsc) {
> +	if (dsc) {
>   		/*
>   		 * In case of Display Stream Compression (DSC), we would use
>   		 * 2 DSC encoders, 2 layer mixers and 1 interface
> @@ -605,6 +618,7 @@ static int dpu_encoder_virt_atomic_check(
>   	struct drm_display_mode *adj_mode;
>   	struct msm_display_topology topology;
>   	struct dpu_global_state *global_state;
> +	struct drm_dsc_config *dsc;
>   	int i = 0;
>   	int ret = 0;
>   
> @@ -640,7 +654,9 @@ static int dpu_encoder_virt_atomic_check(
>   		}
>   	}
>   
> -	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state);
> +	dsc = dpu_encoder_get_dsc_config(drm_enc);
> +
> +	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state, dsc);
>   
>   	/*
>   	 * Release and Allocate resources on every modeset
> @@ -1056,6 +1072,8 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
>   
>   	trace_dpu_enc_mode_set(DRMID(drm_enc));
>   
> +	dpu_enc->dsc = dpu_encoder_get_dsc_config(drm_enc);
> +
>   	/* Query resource that have been reserved in atomic check step. */
>   	num_pp = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
>   		drm_enc->base.id, DPU_HW_BLK_PINGPONG, hw_pp,
> @@ -1187,6 +1205,8 @@ static void dpu_encoder_virt_atomic_enable(struct drm_encoder *drm_enc,
>   
>   	dpu_enc = to_dpu_encoder_virt(drm_enc);
>   
> +	dpu_enc->dsc = dpu_encoder_get_dsc_config(drm_enc);

Let's have a single place where dpu_enc->dsc is set. I have slight 
preference for atomic_enable, but atomic_mode_set is fine too.

> +
>   	mutex_lock(&dpu_enc->enc_lock);
>   	cur_mode = &dpu_enc->base.crtc->state->adjusted_mode;
>   
> @@ -2109,8 +2129,10 @@ void dpu_encoder_helper_phys_cleanup(struct dpu_encoder_phys *phys_enc)
>   					phys_enc->hw_pp->merge_3d->idx);
>   	}
>   
> -	if (dpu_enc->dsc)
> +	if (dpu_enc->dsc) {
>   		dpu_encoder_unprep_dsc(dpu_enc);
> +		dpu_enc->dsc = NULL;
> +	}
>   
>   	intf_cfg.stream_sel = 0; /* Don't care value for video mode */
>   	intf_cfg.mode_3d = dpu_encoder_helper_get_3d_blend_mode(phys_enc);

--
With best wishes
Dmitry