From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH] ARM: dts: exynos5422-odroid*: remove fimd node Date: Thu, 26 Nov 2015 11:39:26 -0300 Message-ID: <5657199E.8040503@osg.samsung.com> References: <1447151049-25370-1-git-send-email-m.szyprowski@samsung.com> <56428F34.7060003@samsung.com> <56531B1F.9050502@osg.samsung.com> <5653DEA2.6060802@samsung.com> <5653E851.4070608@osg.samsung.com> <5657173F.6070301@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from lists.s-osg.org ([54.187.51.154]:59342 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751609AbbKZOjd (ORCPT ); Thu, 26 Nov 2015 09:39:33 -0500 In-Reply-To: <5657173F.6070301@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Marek Szyprowski , Krzysztof Kozlowski , linux-samsung-soc@vger.kernel.org Cc: Kukjin Kim , Bartlomiej Zolnierkiewicz 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