[PATCH] iommu/arm-smmu-qcom: NULL pointer check for driver data

[Aravind Vijayakumar]

The driver_data is NULL when qcom_adreno_smmu_init_context()
is called before the dev_set_drvdata() from the client driver
and is resulting in kernel crash.

So add a null pointer check to handle the scenario
where the client driver for the GPU SMMU device would
be setting the driver data after the smmu client device
probe is done and not necessarily before that. The function
qcom_adreno_smmu_init_context() assumes that the client
driver always set the driver data using dev_set_drvdata()
before the smmu client device probe, but this assumption
is not always true.

Signed-off-by: Aravind Vijayakumar <quic_aprasann at quicinc.com>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index c71afda79d64..5323f82264ca 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -231,6 +231,9 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 	 */
 
 	priv = dev_get_drvdata(dev);
+	if (!priv)
+		return 0;
+
 	priv->cookie = smmu_domain;
 	priv->get_ttbr1_cfg = qcom_adreno_smmu_get_ttbr1_cfg;
 	priv->set_ttbr0_cfg = qcom_adreno_smmu_set_ttbr0_cfg;
-- 
2.40.1