Re: [PATCH] ARM: dts: exynos5422-odroid*: remove fimd node

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hello,

On 2015-11-24 05:32, Javier Martinez Canillas wrote:
> Hello Krzysztof,
>
> On 11/24/2015 12:50 AM, Krzysztof Kozlowski wrote:
>> On 23.11.2015 22:56, Javier Martinez Canillas wrote:
>>> Hello Krzysztof,
>>>
>>> On 11/10/2015 09:43 PM, Krzysztof Kozlowski wrote:
>>>
>>> [snip]
>>>
>>>> BTW, do you know why we don't have EXYNOS_IOMMU enabled in defconfig?
>>>> Any reasons against?
>>> It was explicitly disabled by commit 6562f3bd396a ("ARM: exynos_defconfig:
>>> Disable IOMMU support") because Exynos IOMMU support was broken and caused
>>> a BUG on boot, the discussion of the patch is [0].
>> Right, now I remember.
>>
>>
>>> But I just tested booting a v4.4-rc2 kernel on an Exynos5800 Peach Pi with
>>> Exynos IOMMU enabled and the machine boots, display is working and
>>> /sys/kernel/iommu_grups/*/devices shows that the devices were correctly
>>> attached to an IOMMU group so things seems to have been sorted out now.
>>>
>>> So it seems that EXYNOS_IOMMU could be enabled again. It would be good to
>>> give such a patch a spin at kernelci before posting IMHO though just to be
>>> sure there are no issues remaining.
>> Yes for enabling. No for testing only on kernelci. Booting is not a
>> sufficient test in this case. I would expect testing also display - at
> Sorry if I didn't explain myself clearly. I didn't mean that kernelci was
> enough to test Exynos IOMMU support, what I said is that would be nice to
> have some boot coverage besides the normal manual (or automated) display
> testing that someone could do on available platforms as discussed over IRC.
>
>> least some frame buffer console on DP or HDMI (or whatever output could
>> be generated... Xorg/Wayland would be better of course). You need it
> Yes, as I mentioned in the previous email, I tested display (with X) on an
> Exynos5800 Peach Pi. I don't have a rootfs with wayland/weston handy but I
> could prepare one tomorrow to give a try.
>
>> because display and camera (including complementary modules like JPEG,
>> MFC etc) are actually the only users of Exynos IOMMU in mainline.
>>
> Do you have some test cases for MFC? I know that Gstreamer has support
> for it but I don't know what Gst pipelines I can use to test if all is
> working correctly.

Please note that mainline driver for MFC doesn't work with IOMMU enabled 
yet.
I plan to finish a patch for it when I find some free time.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland