Re: [PATCH 0/4] iommu: tegra-gart cleanups

[Robin Murphy <robin.murphy@arm.com>]

On 2023-05-16 10:53, Nicolas Chauvet wrote:
> Le lun. 15 mai 2023 à 14:57, Robin Murphy <robin.murphy@arm.com> a écrit :
>>
>> Hi all,
>>
>> For the sake of discussion, here's my irrational pet project to bring
>> the tegra-gart driver right up to date as an example of a
>> properly-implemented IOMMU driver for a non-isolated address space. Part
>> of that irrationality is that I don't even own any hardware which uses
>> this driver, so it's only build-tested :)
>>
>> Thanks,
>> Robin.
>>
>>
>> Robin Murphy (4):
>>    iommu/tegra-gart: Add default identity domain support
>>    iommu/tegra-gart: Improve domain support
>>    iommu/tegra-gart: Generalise domain support
>>    iommu: Clean up force_aperture confusion
>>
>>   drivers/iommu/dma-iommu.c    |  19 ++--
>>   drivers/iommu/mtk_iommu_v1.c |   4 +
>>   drivers/iommu/sprd-iommu.c   |   1 +
>>   drivers/iommu/tegra-gart.c   | 162 +++++++++++++++++++----------------
>>   4 files changed, 99 insertions(+), 87 deletions(-)
> 
> 
> For what it worth, I've tried to test this serie with "grate patches"
> (1) rebased on top on 6.4-rc2, that would make use of the tegra-gart.
> That was on PAZ00 (with only 512M of RAM and 96M CMA still allocated).
> Unfortunately, this lead to the following errors with display problems
> (no character displayed in lxt-terminal and etc)

Thanks for testing - it's quite possible I've made a silly mistake 
somewhere, but just to double-check, does the same happen with the 
existing driver if you boot with "tegra-gart.gart_debug=1" (or at least 
enable the parameter via sysfs before the DRM driver gets going)?

Thanks,
Robin.

> [  888.691348] tegra-mc 7000f000.memory-controller: gart: Page entry is in-use
> [  888.698400] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> mapping failed 4294967274 262144
> [  888.707365] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> failed size 262144: -12
> [  888.716735] tegra-mc 7000f000.memory-controller: gart: Page entry is in-use
> [  888.723800] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> mapping failed 4294967274 262144
> [  888.733156] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> failed size 262144: -12
> [  889.055247] tegra-mc 7000f000.memory-controller: gart: Page entry is in-use
> [  889.062296] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> mapping failed 4294967274 262144
> [  889.071266] [drm:tegra_bo_gart_map_locked [tegra_drm]] *ERROR*
> failed size 262144: -12
> 
> (1) https://github.com/grate-driver/linux