From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: [PATCH 1/1] ARM: exynos_defconfig: Disable IOMMU support Date: Tue, 17 Feb 2015 14:08:03 +0100 Message-ID: <1424178483.19861.1.camel@AMDC1943> References: <1424173109-30347-1-git-send-email-javier.martinez@collabora.co.uk> <1424175623.14482.4.camel@AMDC1943> <54E33A79.3060904@collabora.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.w1.samsung.com ([210.118.77.13]:42995 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752294AbbBQNII (ORCPT ); Tue, 17 Feb 2015 08:08:08 -0500 In-reply-to: <54E33A79.3060904@collabora.co.uk> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Javier Martinez Canillas Cc: Kukjin Kim , Olof Johansson , Marek Szyprowski , Andreas Faerber , linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org On wto, 2015-02-17 at 13:56 +0100, Javier Martinez Canillas wrote: > Hello Krzysztof, > > On 02/17/2015 01:20 PM, Krzysztof Kozlowski wrote: > > On wto, 2015-02-17 at 12:38 +0100, Javier Martinez Canillas wrote: > >> Enabling Exynos DRM IOMMU support for Exynos is currently broken and > >> causes a BUG on exynos-iommu driver. This was not an issue since the > >> options was disabled in exynos_defconfig but after commit 8dcc14f82f06 > >> ("drm/exynos: IOMMU support should not be selectable by user"), it is > >> selected if EXYNOS_IOMMU is enabled which is in exynos_defconfig. > >> > >> So a kernel built using exynos_defconfig after the mentioned commit > >> fails to boot [0]. Disable IOMMU support in Exynos defconfig until > >> things get sorted out. > > > > On which board you got this error? > > > > Sorry, I should had mention it in the commit message. I get that error > with at least Exynos5800 Peach Pi, Exynos5420 Peach Pit and Exynos5250 > Snow Chromebooks with today's next (next-20150217). > > The problem is that the Exynos IOMMU driver does not set a struct > exynos_iommu_owner in dev.archdata.iommu but __exynos_sysmmu_enable() > has a BUG_ON(!has_sysmmu(dev)). > > Marek's series [1] solves this issue by filling sysmmu devices from DT > but causes boot failures on the Exynos Chromebooks because the display > is left enabled by the bootloader [2]. > > So I think that this option should be disabled until is known to not > cause issues on any platform. Sure, I am completely fine with that change. I just wanted to know the hardware. Anyway Marek already acked this I won't duplicate the effort :). Best regards, Krzysztof