Hello Marek,
On 11/26/2015 11:29 AM, Marek Szyprowski wrote:
> 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.
>
Thanks a lot for the information. Then that's a reason to not enable IOMMU
by default in the defconfig until the MFC driver works correctly with that.
> Best regards
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
