Re: [PATCH v2 09/13] iommu/rockchip: Use iommu_group_get_for_dev() for add_device

[JeffyChen]

On 01/17/2018 08:47 PM, JeffyChen wrote:

+static struct iommu_group *rk_iommu_device_group(struct device *dev)
+{
+    struct iommu_group *group;
+    int ret;
+
+    group = iommu_group_get(dev);
+    if (!group) {

This check is pointless - if dev->iommu_group were non-NULL you wouldn't
have been called in the first place.
right, it's allocated in the probe.
oops, sorry, i see, this is not needed because device_group() is only be 
called when iommu_group_get() returns NULL