On Wed, Nov 09, 2016 at 11:54:20AM +0530, Sricharan wrote: > >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > >> index 71ce4b6..a1d0b3c 100644 > >> --- a/drivers/iommu/arm-smmu.c > >> +++ b/drivers/iommu/arm-smmu.c > >> @@ -1516,8 +1516,10 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev) > >> group = smmu->s2crs[idx].group; > >> } > >> > >> - if (group) > >> + if (group) { > >> + iommu_group_get_by_id(iommu_group_id(group)); > >> return group; > > > >This might as well just be inline, i.e.: > > > > return iommu_group_get_by_id(iommu_group_id(group)); > > > >It's a shame we have to go all round the houses when we have the group > >right there, but this is probably the most expedient fix. I guess we can > >extend the API with some sort of iommu_group_get(group) overload in > >future if we really want to. > > > > ok, i can send this fix separately then. Otherwise, Will was suggesting on the > other thread that there should probably be a separate API to increment > the group refcount or get the group from the existing aliasing device. > As per me adding the api, looks like another option or post the above ? I think adding a new function to the API is the way to go -- having code like what you propose above littered around the drivers is hard to read and pretty error-prone, since it looks like a NOP to people who aren't already thinking about ref counts. Will -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html