From mboxrd@z Thu Jan 1 00:00:00 1970 From: m.szyprowski@samsung.com (Marek Szyprowski) Date: Wed, 22 Oct 2014 11:54:34 +0200 Subject: [PATCH v2 11/18] iommu: exynos: remove useless device_add/remove callbacks In-Reply-To: <2779319.yKiT9EDCse@wuerfel> References: <1410868485-4143-1-git-send-email-m.szyprowski@samsung.com> <1410868485-4143-12-git-send-email-m.szyprowski@samsung.com> <1413969300.31696.10.camel@gmail.com> <2779319.yKiT9EDCse@wuerfel> Message-ID: <54477EDA.3060104@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On 2014-10-22 11:26, Arnd Bergmann wrote: > On Wednesday 22 October 2014 11:15:00 Alban Browaeys wrote: >> Le mardi 16 septembre 2014 ? 13:54 +0200, Marek Szyprowski a ?crit : >>> The driver doesn't need to do anything important in device add/remove >>> callbacks, because initialization will be done from device-tree specific >>> callbacks added later. IOMMU groups created by current code were never >>> used. >>> >>> Signed-off-by: Marek Szyprowski >> >> The exyons iommu init fails if those are removed, that is it never reach >> init_done: >> 1. exynos_iommu_setup >> 2. - exynos_iommu_init >> 3. ---bus_set_iommu >> 4. ------ add_iommu_group >> >> that is (4) add_iommu_group returns ENODEV to bus_set_iommu, the latter >> doing so to exynos_iommu_init. Which thus error out before the init_done >> is set to true. > On a related note, I found that the exynos iommu driver does not check > for the presence of an exynos iommu before calling bus_set_iommu, > and this breaks multiplatform kernels. > > Please fix. For the time being please apply this patch: https://lkml.org/lkml/2014/8/5/163 The proper solution will be applied when driver will be adapted to common of iommu support, which is still under discussion. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland