[PATCH 2/2] drm/msm/gpu: Fix crash during system suspend after unbind

[Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>]

In adreno_unbind, we should clean up gpu device's drvdata to avoid
accessing a stale pointer during system suspend. Also, check for NULL
ptr in both system suspend/resume callbacks.

Signed-off-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
---
Rebased on msm-next + some external fixes to boot sc7280 device.

 drivers/gpu/drm/msm/adreno/adreno_device.c | 10 +++++++++-
 drivers/gpu/drm/msm/msm_gpu.c              |  2 ++
 drivers/gpu/drm/msm/msm_gpu.h              |  4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index 24b489b..6288064 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -679,6 +679,9 @@ static int adreno_system_suspend(struct device *dev)
 	struct msm_gpu *gpu = dev_to_gpu(dev);
 	int remaining, ret;
 
+	if (!gpu)
+		return 0;
+
 	suspend_scheduler(gpu);
 
 	remaining = wait_event_timeout(gpu->retire_event,
@@ -700,7 +703,12 @@ static int adreno_system_suspend(struct device *dev)
 
 static int adreno_system_resume(struct device *dev)
 {
-	resume_scheduler(dev_to_gpu(dev));
+	struct msm_gpu *gpu = dev_to_gpu(dev);
+
+	if (!gpu)
+		return 0;
+
+	resume_scheduler(gpu);
 	return pm_runtime_force_resume(dev);
 }
 
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 0098ee8..021f4e2 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -997,4 +997,6 @@ void msm_gpu_cleanup(struct msm_gpu *gpu)
 	}
 
 	msm_devfreq_cleanup(gpu);
+
+	platform_set_drvdata(gpu->pdev, NULL);
 }
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index ff911e73..58a72e6 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -280,6 +280,10 @@ struct msm_gpu {
 static inline struct msm_gpu *dev_to_gpu(struct device *dev)
 {
 	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(dev);
+
+	if (!adreno_smmu)
+		return NULL;
+
 	return container_of(adreno_smmu, struct msm_gpu, adreno_smmu);
 }
 
-- 
2.7.4