Hi,

Today's linux-next (next-20150721) encounters boot failures on Exynos
Octa (Exynos5422) based boards. The boards hangs. I bisected it to:

d80167b85024982c5f18d0481a5c248100360118 is the first bad commit
commit d80167b85024982c5f18d0481a5c248100360118
Author: Joonyoung Shim <jy0922.shim@samsung.com>
Date:   Thu Jul 2 21:49:39 2015 +0900

    drm/exynos: remove drm_iommu_attach_device_if_possible

    Already drm_iommu_attach_device checks whether support iommu internally.
    It should clear channels always regardless iommu support. We didn't know
    because we can detect the problem when iommu is enabled, so we don't
    have to use drm_iommu_attach_device_if_possible and then we can remove
    drm_iommu_attach_device_if_possible and clear_channels function pointer.

    Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
    Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
    Signed-off-by: Inki Dae <inki.dae@samsung.com>

:040000 040000 83379efbf4960f58d680371628ec04387935bd53
da03c338b88e7cb6bda895b3dd52d78d9b6eba30 M drivers


Config: exynos
Boot log from Odroid XU3-Lite attached.

Any hints or ideas?

Best regards,
Krzysztof