Messages in this thread |  | | Date | Thu, 14 Dec 2017 19:00:42 +0100 | From | Krzysztof Kozlowski <> | Subject | Re: [PATCH] ARM: exynos_defconfig - enable CONFIG_EXYNOS_IOMMU |
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On Wed, Dec 13, 2017 at 10:42:33AM +0100, Marek Szyprowski wrote: > Hi Shuah, > > On 2017-12-12 22:31, Shuah Khan wrote: > > EXYNOS_IOMMU is disabled in exynos_defconfig since it is known to cause > > boot failures on Exynos Chrome-books. The recommendation is for IOMMU to > > be enabled manually on systems as needed. > > > > A recent exynos_drm change added a warning message when EXYNOS_IOMMU is > > disabled. It is necessary to enable it to avoid the warning messages. > > A few initial tests have shown that enabling EXYNOS_IOMMU might be safe > > on Exynos Chrome-books. > > > > Enable CONFIG_EXYNOS_IOMMU in exynos_defconfig. > > > > Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> > > Due to some other changes in the order of operations during boot process, > power domains are initialized very early and because of the temporary > lack of devices (which are not yet added to the system), are turned off. > > This practically stops FIMD for scanning framebuffer very early during > boot, before IOMMU gets initialized and "solves" the issue, which was > the reason to disable Exynos IOMMU by default. > > Like I've already said, I've checked Exynos Snow Chromebook boots fine > with IOMMU support enabled, both with v4.15-rc3 and linux-next. > > Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Thanks, applied with rephrased and extended message using Marek's explanation.
Best regards, Krzysztof
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