Re: [PATCH v1 2/2] iommu/tegra-smmu: Revert workaround that was needed for Nyan Big Chromebook

Dmitry Osipenko
2021-04-24T20:27:18Z

23.04.2021 18:23, Dmitry Osipenko пишет:
> 23.04.2021 18:01, Guillaume Tucker пишет:
>> On 02/04/2021 15:40, Dmitry Osipenko wrote:
>>> 01.04.2021 11:55, Nicolin Chen пишет:
>>>> On Mon, Mar 29, 2021 at 02:32:56AM +0300, Dmitry Osipenko wrote:
>>>>> The previous commit fixes problem where display client was attaching too
>>>>> early to IOMMU during kernel boot in a multi-platform kernel configuration
>>>>> which enables CONFIG_ARM_DMA_USE_IOMMU=y. The workaround that helped to
>>>>> defer the IOMMU attachment for Nyan Big Chromebook isn't needed anymore,
>>>>> revert it.
>>>>
>>>> Sorry for the late reply. I have been busy with downstream tasks.
>>>>
>>>> I will give them a try by the end of the week. Yet, probably it'd
>>>> be better to include Guillaume also as he has the Nyan platform.
>>>>
>>>
>>> Indeed, thanks. Although, I'm pretty sure that it's the same issue which
>>> I reproduced on Nexus 7.
>>>
>>> Guillaume, could you please give a test to these patches on Nyan Big?
>>> There should be no EMEM errors in the kernel log with this patches.
>>>
>>> https://patchwork.ozlabs.org/project/linux-tegra/list/?series=236215
>>
>> So sorry for the very late reply. I have tried the patches but
>> hit some issues on linux-next, it's not reaching a login prompt
>> with next-20210422. So I then tried with next-20210419 which
>> does boot but shows the IOMMU error:
>>
>> <6>[ 2.995341] tegra-dc 54200000.dc: Adding to iommu group 1
>> <4>[ 3.001070] Failed to attached device 54200000.dc to IOMMU_mapping
>>
>> https://lava.collabora.co.uk/scheduler/job/3570052#L1120
>>
>> The branch I'm using with the patches applied can be found here:
>>
>> https://gitlab.collabora.com/gtucker/linux/-/commits/next-20210419-nyan-big-drm-read/
>>
>> Hope this helps, let me know if you need anything else to be
>> tested.
>
>
> Hello Guillaume,
>
> The current linux-next doesn't boot on all ARM (AFAIK), the older
> next-20210413 works. The above message should be unrelated to the boot
> problem. It should be okay to ignore that message as it should be
> harmless in yours case.
>

Although, the 20210419 should be good.

Thierry, do you know what those SOR and Nouveau issues are about?