On Wed, May 20, 2015 at 03:10:24PM +0900, Alexandre Courbot wrote:
The lack of IOMMU API support can make nouveau_platform_probe_iommu() fail to compile because struct iommu_ops is then empty. Fix this by skipping IOMMU probe in that case - lack of IOMMU on platform devices is sub-optimal, but is not an error.
Signed-off-by: Alexandre Courbot acourbot@nvidia.com
This is an alternative to https://lkml.org/lkml/2015/5/19/484. Most users of Nouveau do not care about IOMMU support, so we should not impose that option on them.
drm/nouveau/nouveau_platform.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/nouveau/nouveau_platform.c b/drivers/gpu/drm/nouveau/nouveau_platform.c index 775277f1edb0..dcfbbfaf1739 100644 --- a/drivers/gpu/drm/nouveau/nouveau_platform.c +++ b/drivers/gpu/drm/nouveau/nouveau_platform.c @@ -92,6 +92,8 @@ static int nouveau_platform_power_down(struct nouveau_platform_gpu *gpu) return 0; }
+#if IS_ENABLED(CONFIG_IOMMU_API)
static void nouveau_platform_probe_iommu(struct device *dev, struct nouveau_platform_gpu *gpu) { @@ -158,6 +160,20 @@ static void nouveau_platform_remove_iommu(struct device *dev, } }
+#else
+static void nouveau_platform_probe_iommu(struct device *dev,
struct nouveau_platform_gpu *gpu)+{ +}
+static void nouveau_platform_remove_iommu(struct device *dev,
struct nouveau_platform_gpu *gpu)+{ +}
+#endif
Since these are all static functions, perhaps an "if (IS_ENABLED(...))" would work here? That way you'd get compile coverage of the code in all cases.
But perhaps that doesn't work for IOMMU. I have a vague memory of running across something like this before and IOMMU has this quirk of defining struct iommu_ops as empty if IOMMU_API is deselected so you'll probably get compiler errors unless you actually preprocess the code out.
Thierry