[PATCH v2 09/13] iommu/omap: Constrain return value of ->attach_dev()

[Nicolin Chen <nicolinc@nvidia.com>]

Ensure attach_dev() callback functions only return errno values expected
from the attach_dev() op. In particular, only return -EINVAL when we are
sure that the device is incompatible with the domain.

Also drop any dev_err next to -EINVAL, following the attach_dev op kdocs.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/omap-iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index d9cf2820c02e..e97ebb2c0133 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1464,15 +1464,14 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 
 	if (!arch_data || !arch_data->iommu_dev) {
 		dev_err(dev, "device doesn't have an associated iommu\n");
-		return -EINVAL;
+		return -ENODEV;
 	}
 
 	spin_lock(&omap_domain->lock);
 
 	/* only a single client device can be attached to a domain */
 	if (omap_domain->dev) {
-		dev_err(dev, "iommu domain is already attached\n");
-		ret = -EBUSY;
+		ret = -EINVAL;
 		goto out;
 	}
 
@@ -1480,6 +1479,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	if (ret) {
 		dev_err(dev, "failed to allocate required iommu data %d\n",
 			ret);
+		ret = -ENODEV;
 		goto init_fail;
 	}
 
@@ -1490,6 +1490,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		ret = omap_iommu_attach(oiommu, iommu->pgtable);
 		if (ret) {
 			dev_err(dev, "can't get omap iommu: %d\n", ret);
+			ret = -ENODEV;
 			goto attach_fail;
 		}
 
-- 
2.17.1