On Tue, Oct 14, 2014 at 04:02:40PM +0800, Daniel Kurtz wrote: > +static void rk_iommu_detach_device(struct iommu_domain *domain, > + struct device *dev) > +{ > + struct rk_iommu *iommu = dev_get_drvdata(dev->archdata.iommu); > + struct rk_iommu_domain *rk_domain = domain->priv; > + unsigned long flags; > + > + /* Allow 'virtual devices' (eg drm) to detach from domain */ > + if (!iommu) > + return; > + > + iommu->domain = NULL; I guess this line is a left-over? Setting iommu->domain to NULL here before you disabled the IOMMU interrupt is racy. To be fully secure, you should make sure that no interrupt handler is still running after you disabled the IOMMU irq and before setting iommu->domain = NULL. Other than that the code looks good. Joerg -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html