[PATCH 3/5] drm/msm/dpu: add support for MDP_TOP blackhole

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On sm8450 a register block was removed from MDP TOP. Accessing it during
snapshotting results in NoC errors / immediate reboot. Skip accessing
these registers during snapshot.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h |  1 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c        | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
index 38aa38ab1568..4730f8268f2a 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
@@ -92,6 +92,7 @@ enum {
 	DPU_MDP_UBWC_1_0,
 	DPU_MDP_UBWC_1_5,
 	DPU_MDP_AUDIO_SELECT,
+	DPU_MDP_PERIPH_0_REMOVED,
 	DPU_MDP_MAX
 };
 
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index 5e6e2626151e..b0bb693c10ac 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -939,8 +939,15 @@ static void dpu_kms_mdp_snapshot(struct msm_disp_state *disp_state, struct msm_k
 		msm_disp_snapshot_add_block(disp_state, cat->wb[i].len,
 				dpu_kms->mmio + cat->wb[i].base, "wb_%d", i);
 
-	msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len,
-			dpu_kms->mmio + cat->mdp[0].base, "top");
+	if (top->caps->features & BIT(DPU_MDP_PERIPH_0_REMOVED)) {
+		msm_disp_snapshot_add_block(disp_state, 0x380,
+				dpu_kms->mmio + cat->mdp[0].base, "top");
+		msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len - 0x3a8,
+				dpu_kms->mmio + cat->mdp[0].base + 0x3a8, "top_2");
+	} else {
+		msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len,
+				dpu_kms->mmio + cat->mdp[0].base, "top");
+	}
 
 	pm_runtime_put_sync(&dpu_kms->pdev->dev);
 }
-- 
2.35.1