[PATCH v1 2/3] drm/msm/dpu: retrieve DSI DSC struct at atomic_check()

[Kuogee Hsieh]

At current implementation, DSI DSC struct is populated at display setup
during system bootup. This mechanism works fine with embedded display.
But will run into problem with plugin/unplug oriented external display,
such as DP, due to DSC struct will become stale once external display
unplugged. New DSC struct has to be re populated to reflect newer external
display which just plugged in. Move retrieving of DSI DSC struct to
atomic_check() so that same mechanism will work for both embedded display
and external plugin/unplug oriented display.

Signed-off-by: Kuogee Hsieh <quic_khsieh at quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 15 ++++++++++++++-
 drivers/gpu/drm/msm/msm_drv.h               |  6 ++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 3b416e1..2927d20 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -16,6 +16,8 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_file.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_fixed.h>
 
 #include "msm_drv.h"
 #include "dpu_kms.h"
@@ -639,6 +641,15 @@ static int dpu_encoder_virt_atomic_check(
 		}
 	}
 
+	if (dpu_enc->disp_info.intf_type == DRM_MODE_ENCODER_DSI) {
+		struct drm_bridge *bridge;
+
+		if (!dpu_enc->dsc) {
+			bridge = drm_bridge_chain_get_first_bridge(drm_enc);
+			dpu_enc->dsc = msm_dsi_bridge_get_dsc_config(bridge);
+		}
+	}
+
 	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state);
 
 	/*
@@ -2121,8 +2132,10 @@ 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);
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index e13a8cb..5a7c1f4 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -341,6 +341,7 @@ bool msm_dsi_is_cmd_mode(struct msm_dsi *msm_dsi);
 bool msm_dsi_is_bonded_dsi(struct msm_dsi *msm_dsi);
 bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi);
 struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi);
+struct drm_dsc_config *msm_dsi_bridge_get_dsc_config(struct drm_bridge *bridge);
 #else
 static inline void __init msm_dsi_register(void)
 {
@@ -374,6 +375,11 @@ static inline struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_
 {
 	return NULL;
 }
+
+struct drm_dsc_config *msm_dsi_bridge_get_dsc_config(struct drm_bridge *bridge)
+{
+	return NULL;
+}
 #endif
 
 #ifdef CONFIG_DRM_MSM_DP
-- 
2.7.4