From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Wed, 22 Oct 2014 11:26:53 +0200
Subject: [PATCH v2 11/18] iommu: exynos: remove useless device_add/remove
 callbacks
In-Reply-To: <1413969300.31696.10.camel@gmail.com>
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>
Message-ID: <2779319.yKiT9EDCse@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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 <m.szyprowski@samsung.com>
> 
> 
> 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.

	Arnd