Hi Joerg, On 30/08/17 13:09, Joerg Roedel wrote: > Hi Jon, > > On Wed, Aug 30, 2017 at 12:04:38PM +0100, Jon Hunter wrote: >> With next-20170829 I am seeing several Tegra boards crashing [0][1] on >> boot in tegra_smmu_probe() and the bisect is point to this commit. Looks >> like there maybe a sequence problem between calls to bus_set_iommu() and >> iommu_device_add_sysfs() which results in a NULL pointer dereference. > > Thanks for the report. Can you please test whether the patch below > fixes the problem? > > Thanks, > > Joerg > > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > index 2802e12e6a54..48ffbe95a663 100644 > --- a/drivers/iommu/tegra-smmu.c > +++ b/drivers/iommu/tegra-smmu.c > @@ -949,10 +949,6 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev, > > tegra_smmu_ahb_enable(); > > - err = bus_set_iommu(&platform_bus_type, &tegra_smmu_ops); > - if (err < 0) > - return ERR_PTR(err); > - > err = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, dev_name(dev)); > if (err) > return ERR_PTR(err); > @@ -965,6 +961,10 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev, > return ERR_PTR(err); > } > > + err = bus_set_iommu(&platform_bus_type, &tegra_smmu_ops); > + if (err < 0) > + return ERR_PTR(err); > + Yes I can confirm that this fixes the crash. I assume that you will fix the error path for bus_set_iommu() above as I believe now it needs to call iommu_device_sysfs_remove(). Cheers! Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
