On Thu, Aug 20, 2020 at 06:25:19PM +0100, Robin Murphy wrote: > On 2020-08-20 17:53, Sakari Ailus wrote: > > Hi Robin, > > > > On Thu, Aug 20, 2020 at 04:08:36PM +0100, Robin Murphy wrote: > > > Now that arch/arm is wired up for default domains and iommu-dma, devices > > > behind IOMMUs will get mappings set up automatically as appropriate, so > > > there is no need for drivers to do so manually. > > > > > > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > > > > Thanks for the patch. > > Many thanks for testing so quickly! > > > I haven't looked at the details but it seems that this causes the buffer > > memory allocation to be physically contiguous, which causes a failure to > > allocate video buffers of entirely normal size. I guess that was not > > intentional? > > Hmm, it looks like the device ends up with the wrong DMA ops, which implies > something didn't go as expected with the earlier IOMMU setup and default > domain creation. Chances are that either I missed some subtlety in the > omap_iommu change, or I've fundamentally misjudged how the ISP probing works > and it never actually goes down the of_iommu_configure() path in the first > place. Do you get any messages from the IOMMU layer earlier on during boot? I do get these: [ 2.934936] iommu: Default domain type: Translated [ 2.940917] omap-iommu 480bd400.mmu: 480bd400.mmu registered [ 2.946899] platform 480bc000.isp: Adding to iommu group 0 -- Sakari Ailus