Hello Marek,
On Mon, May 18, 2015 at 3:26 PM, Marek Szyprowski m.szyprowski@samsung.com wrote:
Hello,
On 2015-05-11 18:00, Javier Martinez Canillas wrote:
Hello Marek,
On Mon, May 4, 2015 at 10:15 AM, Marek Szyprowski m.szyprowski@samsung.com wrote:
Hello Everyone,
This is yet another attempt to get Exynos SYSMMU driver with integrated with IOMMU & DMA-mapping subsystems. The main change from previous version is addition of the patches to define iommu-mapping, which need to be created during system boot to avoid IOMMU fault by devices, which has been left enabled by bootloader (i.e. framebuffer displaying slash screen).
Patches has been also rebased onto v4.1-rc2 with 'arm: dma-mapping: fix off-by-one check in arm_setup_iommu_dma_ops' patch applied (see commit 1424532b2163bf1580f4b1091a5801e12310fac5 on fixes branch in git://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-arm.git, more information: http://www.spinics.net/lists/arm-kernel/msg414722.html).
All patches are also available in the following git repository: https://git.linaro.org/people/marek.szyprowski/linux-srpol.git branch v4.1-exynos-iommu.
Thanks for the new series, this time I didn't get a system hang when I enabled both CONFIG_DRM_EXYNOS_FIMD and CONFIG_DRM_EXYNOS_DP on my Exynos5420 Peach Pit Chromebook.
The system finished booting and I have both a console on the HDMI and eDP/LVDS displays. But if I try to start X or weston, I again have a completele system hang with no output on the serial console. This works correctly without your IOMMU series.
And again disabling CONFIG_DRM_EXYNOS_DP or CONFIG_DRM_EXYNOS_FIMD avoids the system to hang. If I only have CONFIG_DRM_EXYNOS_HDMI enabled, then I can start X with out issues and is displayed correctly in the HDMI output.
So it seems your workaround for the boot-loader leaving the FIMD dma engine enabled is not enough? I'm not a graphics person so I can think of the top of my head what could trigger the system hang when X or weston are executed so I wondered if you have any ideas.
This means that there are more bugs in Exynos DRM driver. Once Exynos DRM driver is probed, the initial iommu domain with identity mapping is destroyed and Exynos DRM manages it's own iommu domain, so it has nothing to my mentioned patch.
I see, thanks for the explanation.
I will try to check this issue.
Great, thanks a lot for taking a look.
Best regards
Marek Szyprowski, PhD Samsung R&D Institute Poland
Best regards, Javier