On Mon, Aug 19, 2013 at 11:39:49AM +1000, Alexey Kardashevskiy wrote: >On 08/19/2013 11:29 AM, Wei Yang wrote: >> On Fri, Aug 16, 2013 at 08:15:36PM +1000, Alexey Kardashevskiy wrote: >>> On 08/16/2013 08:08 PM, Wei Yang wrote: >>>> --- >>>> arch/powerpc/kernel/iommu.c | 3 ++- >>>> 1 files changed, 2 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c >>>> index b20ff17..5abf7c3 100644 >>>> --- a/arch/powerpc/kernel/iommu.c >>>> +++ b/arch/powerpc/kernel/iommu.c >>>> @@ -1149,7 +1149,8 @@ static int iommu_bus_notifier(struct notifier_block >>>> *nb, >>>> case BUS_NOTIFY_ADD_DEVICE: >>>> return iommu_add_device(dev); >>>> case BUS_NOTIFY_DEL_DEVICE: >>>> - iommu_del_device(dev); >>>> + if (dev->iommu_group) >>>> + iommu_del_device(dev); >>>> return 0; >>>> default: >>>> return 0; >>>> >>> >>> This one seems redundant, no? >> >> Sorry for the late. >> >> Yes, these two patches have the same purpose to guard the system, while in >> two >> different places. One is in powernv platform, the other is in the generic >> iommu >> driver. >> >> The one in powernv platform is used to correct the original logic. >> >> The one in generic iommu driver is to keep system safe in case other >> platform to >> call iommu_group_remove_device() without the check. > > >But I am moving bus notifier to powernv code (posted a patch last week, >otherwise Freescale's IOMMU conflicted) so this won't be the case.
Yes, I see the patch. This means other platforms, besides powernv, will check the dev->iommu_group before remove the device? This would be a convention? If this is the case, the second patch is enough. We don't need to check it in generic iommu driver. Since I am not very familiar with the code convention, I post these two patches together. This doesn't mean I need to push both of them. Your comments are welcome, lets me understand which one is more suitable in this case. > > > >-- >Alexey -- Richard Yang Help you, Help me _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
