On Tue, Dec 12, 2017 at 9:47 AM, Marek Szyprowski m.szyprowski@samsung.com wrote:
Hi Javier,
On 2017-12-12 09:00, Javier Martinez Canillas wrote:
On Tue, Dec 12, 2017 at 8:54 AM, Marek Szyprowski m.szyprowski@samsung.com wrote:
(...)
This warning has been added intentionally, see following discussions: https://patchwork.kernel.org/patch/10034919/ https://patchwork.kernel.org/patch/10070475/
This means that your test apps should be updated or you should enable Exynos IOMMU support in your config. Maybe it is a good time to finally enable it in exynos_defconfig.
Has the issue that the boot-loader keeps the display controller enabled and scanning pages on the Exynos Chromebooks resolved?
I think that's that preventing to enable it by default in exynos_defconfig since it caused boot failures when enabled on these machines. I don't follow exynos development too closely nowadays so maybe there's a fix in place now.
Not directly. I still didn't find time to properly add support for devices, which were left in-working state (with active DMA transactions) by bootloader, but due to some other changes in the order of operations during boot process, power domains are initialized very early and due to temporary lack of devices (which are not yet added to the system), are turned off. This practically stops FIMD for scanning framebuffer and "solves" this issue.
I've checked now and Exynos Snow Chromebook boots fine with IOMMU support enabled, both with v4.15-rc3 and linux-next.
Then it looks like we could give EXYNOS_IOMMU a try. At least only on exynos_defconfig which would leave multi_v7 as a platform to compare.
Best regards, Krzysztof