drm/msm/dpu: retrieve DSI DSC struct through priv->dsi[0]

Currently struct drm_dsc_config for DSI is populated at display
setup during system boot up. This mechanism works fine with
embedded display but not for pluggable displays as the
struct drm_dsc_config will become stale once external display
is unplugged.

In preparation of adding support for DP DSC support
move storing of DSI DSC struct to atomic_enable() so that same
mechanism will work for both embedded display and pluggable
displays.

Changes in v4:
-- fix checkpatch.pl warning

Changes in v5:
-- delete dpu_encoder_get_dsc_config() from atomic_mode_set
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/543867/
Link: https://lore.kernel.org/r/1687454686-10340-2-git-send-email-quic_khsieh@quicinc.com
[DB: fixed commit message]
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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
@@ -1072,7 +1088,6 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
 		dpu_enc->hw_pp[i] = i < num_pp ? to_dpu_hw_pingpong(hw_pp[i])
 						: NULL;
 
-	if (dpu_enc->dsc) {
 	num_dsc = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
 						drm_enc->base.id, DPU_HW_BLK_DSC,
 						hw_dsc, ARRAY_SIZE(hw_dsc));
@@ -1080,7 +1095,6 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
 		dpu_enc->hw_dsc[i] = to_dpu_hw_dsc(hw_dsc[i]);
 		dsc_mask |= BIT(dpu_enc->hw_dsc[i]->idx - DSC_0);
 	}
-	}
 
 	dpu_enc->dsc_mask = dsc_mask;
 
@@ -1187,6 +1201,8 @@ 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);
+
 	mutex_lock(&dpu_enc->enc_lock);
 	cur_mode = &dpu_enc->base.crtc->state->adjusted_mode;
 
@@ -2108,8 +2124,10 @@ 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);