drm/msm/disp/dpu1: program 3d_merge only if block is attached

Update the 3d merge as active in the data path only if
the hw block is selected in the configuration.

Reported-by: Stephen Boyd <swboyd@chromium.org>
Fixes: 73bfb79 ("msm:disp:dpu1: setup display datapath for SC7180 target")
Signed-off-by: Kalyan Thota <kalyan_t@codeaurora.org>
Message-Id: <1617364493-13518-1-git-send-email-kalyan_t@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c

@@ -496,7 +496,9 @@ static void dpu_hw_ctl_intf_cfg_v1(struct dpu_hw_ctl *ctx,
 
 	DPU_REG_WRITE(c, CTL_TOP, mode_sel);
 	DPU_REG_WRITE(c, CTL_INTF_ACTIVE, intf_active);
-	DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE, BIT(cfg->merge_3d - MERGE_3D_0));
+	if (cfg->merge_3d)
+		DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE,
+			      BIT(cfg->merge_3d - MERGE_3D_0));
 }
 
 static void dpu_hw_ctl_intf_cfg(struct dpu_hw_ctl *ctx,