[PATCH v6 09/11] drm/msm/dpu: add support for MDP_TOP blackhole

[Dmitry Baryshkov]

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.

Tested-by: Vinod Koul <vk...@kernel.org>
Reviewed-by: Vinod Koul <vk...@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dyb...@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h |  3 +++
 drivers/gpu/drm/msm/disp/dpu1/dpu_hwio.h       |  3 +++
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c        | 11 +++++++++--
 3 files changed, 15 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 3b645d5aa9aa..a9d161daf786 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
@@ -83,6 +83,8 @@ enum {
  * @DPU_MDP_UBWC_1_0,      This chipsets supports Universal Bandwidth
  *                         compression initial revision
  * @DPU_MDP_UBWC_1_5,      Universal Bandwidth compression version 1.5
+ * @DPU_MDP_PERIPH_0_REMOVED Indicates that access to periph top0 block results
+ *                        in a failure
  * @DPU_MDP_MAX            Maximum value
 
  */
@@ -93,6 +95,7 @@ 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_hwio.h 
b/drivers/gpu/drm/msm/disp/dpu1/dpu_hwio.h
index 86c423e63b61..feb9a729844a 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hwio.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hwio.h
@@ -63,4 +63,7 @@
 #define MDP_WD_TIMER_4_LOAD_VALUE       0x448
 #define DCE_SEL                         0x450
 
+#define MDP_PERIPH_TOP0                        MDP_WD_TIMER_0_CTL
+#define MDP_PERIPH_TOP0_END            CLK_CTRL3
+
 #endif /*_DPU_HWIO_H */
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c 
b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index b71199511a52..987a74fb7fad 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -927,8 +927,15 @@ 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 (cat->mdp[0].features & BIT(DPU_MDP_PERIPH_0_REMOVED)) {
+               msm_disp_snapshot_add_block(disp_state, MDP_PERIPH_TOP0,
+                               dpu_kms->mmio + cat->mdp[0].base, "top");
+               msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len - 
MDP_PERIPH_TOP0_END,
+                               dpu_kms->mmio + cat->mdp[0].base + 
MDP_PERIPH_TOP0_END, "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