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. Best wishes, Guillaume
