On 10/09/2019 16:34, Rob Clark wrote:
On Tue, Sep 10, 2019 at 1:14 AM Joerg Roedel joro@8bytes.org wrote:
On Fri, Sep 06, 2019 at 02:44:01PM -0700, Rob Clark wrote:
@@ -674,7 +674,7 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev)
mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices);
if (group->domain)
if (group->domain && !(dev->driver && dev->driver->driver_manages_iommu))Hmm, this code usually runs at enumeration time when no driver is attached to the device. Actually it would be pretty dangerous when this code runs while a driver is attached to the device. How does that change make things work for you?
I was seeing this get called via the path driver_probe_device() -> platform_dma_configure() -> of_dma_configure() -> of_iommu_configure() -> iommu_probe_device() -> ...
The only cases I was seeing where dev->driver is NULL where a few places that drivers call of_dma_configure() on their own sub-devices. But maybe there are some other paths that I did not notice?
For the of_iommu flow, it very much depends on your DT layout and driver probe order as to whether you catch the "proper" call from iommu_bus_notifier()/iommu_bus_init() or the late "replay" from of_iommu_configure(). I wouldn't make any assumptions of consistency.
Robin.