On Wed, Aug 16, 2023 at 3:55 PM Aravind Vijayakumar <quic_aprasann@xxxxxxxxxxx> wrote: > > 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@xxxxxxxxxxx> > --- > 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; could this -EPROBE_DEFER instead, or something like that? I think you patch as proposed would result in per-process gpu pgtables silently failing BR, -R > + > 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 >
