On Thu, Aug 21, 2025 at 03:37:04PM -0300, Jason Gunthorpe wrote: > On Thu, Aug 21, 2025 at 08:22:06AM -0700, Nicolin Chen wrote: > > I should have pasted the full piece: > > drivers/gpu/drm/tegra/drm.c-960- /* > > drivers/gpu/drm/tegra/drm.c:961: * If the host1x client is already attached to an IOMMU domain that is > > drivers/gpu/drm/tegra/drm.c-962- * not the shared IOMMU domain, don't try to attach it to a different > > drivers/gpu/drm/tegra/drm.c-963- * domain. This allows using the IOMMU-backed DMA API. > > drivers/gpu/drm/tegra/drm.c-964- */ > > drivers/gpu/drm/tegra/drm.c-965- if (domain && domain->type != IOMMU_DOMAIN_IDENTITY && > > drivers/gpu/drm/tegra/drm.c-966- domain != tegra->domain) > > > > So, the check is two-fold: > > 1) is attached > > 2) is the shared IOMMU domain (tegra->domain?) > > Yea > > iommu_is_domain_currently_attached(dev, tegra->domain) Ah, yea. > > Overall, I feel this would be a big project yet arguably for a low > > reward.. > > Indeed, we can drop a FIXME comment there and leave it as the last > user or something perhaps I see. We could keep it in the library but discourage new callers. I will start with the internal cleanup as we discussed, as a part of this PCI reset series. Then, I will try adding those new helper functions that we've listed here, as a separate series. Thanks Nicolin
