From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
Consider failure of iommu_get_domain_for_dev() as non-critical and
get rid of the warning printout. This allows IOMMU properties to be
included in the DTB even though the kernel is configured with
CONFIG_IOMMU_API=n or in case a particular IOMMU driver refuses to
enable IOMMU support for a certain slave device and returns error
from the ->add_device() callback.
This is only a cosmetic change that removes console warning printouts.
Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---
arch/arm64/mm/dma-mapping.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- 0001/arch/arm64/mm/dma-mapping.c
+++ work/arch/arm64/mm/dma-mapping.c 2017-01-23 20:54:40.060607110 +0900
@@ -827,11 +827,19 @@ static bool do_iommu_attach(struct devic
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
/*
+ * In case IOMMU support is excluded from the kernel or if the device
+ * is not hooked up to any IOMMU group then be silent and keep the
+ * old dma_ops.
+ */
+ if (!domain)
+ return false;
+
+ /*
* If the IOMMU driver has the DMA domain support that we require,
* then the IOMMU core will have already configured a group for this
* device, and allocated the default domain for that group.
*/
- if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) {
+ if (iommu_dma_init_domain(domain, dma_base, size, dev)) {
pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
dev_name(dev));
return false;
