On Thu, Jan 28, 2021 at 09:10:20PM +0000, Will Deacon wrote: > On Wed, Jan 27, 2021 at 05:39:16PM +0800, Yong Wu wrote: > > On Tue, 2021-01-26 at 22:23 +0000, Will Deacon wrote: > > > On Mon, Jan 11, 2021 at 07:18:48PM +0800, Yong Wu wrote: > > > > If group->default_domain exists, avoid reallocate it. > > > > > > > > In some iommu drivers, there may be several devices share a group. Avoid > > > > realloc the default domain for this case. > > > > > > > > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> > > > > --- > > > > drivers/iommu/iommu.c | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > > > index 3d099a31ddca..f4b87e6abe80 100644 > > > > --- a/drivers/iommu/iommu.c > > > > +++ b/drivers/iommu/iommu.c > > > > @@ -266,7 +266,8 @@ int iommu_probe_device(struct device *dev) > > > > * support default domains, so the return value is not yet > > > > * checked. > > > > */ > > > > - iommu_alloc_default_domain(group, dev); > > > > + if (!group->default_domain) > > > > + iommu_alloc_default_domain(group, dev); > > > > > > I don't really get what this achieves, since iommu_alloc_default_domain() > > > looks like this: > > > > > > static int iommu_alloc_default_domain(struct iommu_group *group, > > > struct device *dev) > > > { > > > unsigned int type; > > > > > > if (group->default_domain) > > > return 0; > > > > > > ... > > > > > > in which case, it should be fine? > > > > oh. sorry, I overlooked this. the current code is enough. > > I will remove this patch. and send the next version in this week. > > Thanks very much. > > Actually, looking at this again, if we're dropping this patch and patch 6 > just needs the kfree() moving about, then there's no need to repost. The > issue that Robin and Paul are discussing can be handled separately. Argh, except that this version of the patches doesn't apply :) So after all that, please go ahead and post a v7 ASAP based on this branch: https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-joerg/mtk Will