Am 23.07.2015 um 14:22 schrieb Guillaume Gardet: > Le 23/07/2015 14:16, Andreas Färber a écrit : >> Am 20.07.2015 um 14:28 schrieb Guillaume Gardet: >>> Le 19/07/2015 18:15, Misha Komarovskiy a écrit : >>>> Also lcd screen stays black after kernel start, probably some drm >>>> module still missing. >>> Upstream kernel is broken. :( >> How did you test? Actually there's a known issue that the Exynos IOMMU >> support breaks graphics on the Chromebooks because they enable a >> framebuffer early in bootloaders, before Linux initializes the IOMMU. >> Since some other platforms do need the IOMMU, I fear that we're going to >> need a new kernel flavor... :/ Not sure if that can be scripted as lpae >> minus certain options? > > You mean that if we disable IOMMU in kernel, graphics are working fine?
Hopefully yes. I did not test the latest kernel. It used to be that way ~3 months ago in linux-next.git (cf. linux-samsung-soc) and I doubt it's improved. > CONFIG_DRM_EXYNOS_IOMMU is enabled. Should we disable it for chromebooks? Yes. But at some point that got auto-selected, so it may be necessary to disable IOMMU or the corresponding Exynos sub-option completely. > Maybe some config options compiled as module (which?) and blacklisted > for chromebooks could be ok? Maybe. Someone with a Chromebook needs to sit down and try. :) Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Dilip Upmanyu, Graham Norton; HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
