Hi Robin, On 19/10/2022 18:23, Robin Murphy wrote:
Since commit c7e3ca515e78 ("iommu/tegra: gart: Do not register with bus") quite some time ago, the GART driver has effectively disabled itself to avoid issues with the GPU driver expecting it to work in ways that it doesn't. As of commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration") that bodge no longer works, but really the GPU driver should be responsible for its own behaviour anyway. Make the workaround explicit. Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx> Suggested-by: Dmitry Osipenko <digetx@xxxxxxxxx> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> --- drivers/gpu/host1x/dev.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c index a13fd9441edc..1cae8eea92cf 100644 --- a/drivers/gpu/host1x/dev.c +++ b/drivers/gpu/host1x/dev.c @@ -352,6 +352,10 @@ static struct iommu_domain *host1x_iommu_attach(struct host1x *host) if (!host1x_wants_iommu(host) || domain) return domain;+ /* Our IOMMU usage policy doesn't currently play well with GART */+ if (of_machine_is_compatible("nvidia,tegra20")) + return NULL; + host->group = iommu_group_get(host->dev); if (host->group) { struct iommu_domain_geometry *geometry;
Thanks for sending. I gave this a quick test, but I still see ... [ 2.901739] tegra-gr2d 54140000.gr2d: failed to attach to domain: -19 [ 2.908373] drm drm: failed to initialize 54140000.gr2d: -19 Cheers Jon -- nvpublic
