Re: [PATCH] iommu: fix return error code in iommu_probe_device()

[Yang Yingliang]

On 2020/11/17 17:40, Lu Baolu wrote:
> Hi Yingliang,
>
> On 2020/11/17 10:52, Yang Yingliang wrote:
> > If iommu_group_get() failed, it need return error code
> > in iommu_probe_device().
> >
> > Fixes: cf193888bfbd ("iommu: Move new probe_device path...")
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> > ---
> >   drivers/iommu/iommu.c | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index b53446bb8c6b..6f4a32df90f6 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -253,8 +253,10 @@ int iommu_probe_device(struct device *dev)
> >           goto err_out;
> >         group = iommu_group_get(dev);
> > -    if (!group)
> > +    if (!group) {
> > +        ret = -ENODEV;
>
> Can you please explain why you use -ENODEV here?

Before 79659190ee97 ("iommu: Don't take group reference in 
iommu_alloc_default_domain()"), in

iommu_alloc_default_domain(), if group is NULL, it will return -ENODEV.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/iommu.c?h=v5.10-rc4&id=70b8170e55d3ca9503a53211967faee6b5f18b19

> Best regards,
> baolu
>
> >           goto err_release;
> > +    }
> >         /*
> >        * Try to allocate a default domain - needs support from the
> .