On Fri, Dec 05, 2014 at 09:48:13AM +1100, Gavin Shan wrote: >On Thu, Dec 04, 2014 at 03:21:18PM +0800, Wei Yang wrote: >>On Thu, Dec 04, 2014 at 04:40:35PM +1100, Michael Ellerman wrote: >>>On Thu, 2014-04-12 at 03:24:37 UTC, Wei Yang wrote: >>>> As in commit ac205b7b (PCI: make sriov work with hotplug remove) indicates, >>>> when removing pci devices on a bus which has VFs, we need to remove them in >>>> the reverse order. >>>> >>>> This patch applies this pattern on the hotplug remove path on powerpc arch. >>> >>>So is this is a bug fix? >> >>It hasn't trigger a bug yet. I found this issue during the code reading. When >>VFs are enabled and try to remove a bus with VFs, it will face a problem. So I >>port the change in commit ac205b7b here. >> >>> >>>Where/how have you tested this? >> >>I have tested after change on Power8, the EEH hotplug path works fine for PFs >>now. Will test this when EEH for VFs are ready. >> >>Suggest me to keep it untill EEH for VFs are ready? >> > >Please keep it and resend it (with typo fixed as I pointed) after SRIOV >patchset >gets merged. If SRIOV isn't enabled, we don't need the code change. > >By the way, it's something related to EEH for PFs. When PF and its VFs seat on >same PCI bus, we should remove VFs before putting PF offline in the reversed >order as you did in your code change. Otherwise, PF is put into offline and >its driver disables VFs. We try redoing the removal for VFs in hotplug path, >which would cause race condition. If VFs aren't existing, until your SRIOV >patchset is merged, we don't have this problem. Please correct me if I >understood things wrongly. >
Current code is fine until VF is introduced. Yes, your understanding is correct. >Thanks, >Gavin -- Richard Yang Help you, Help me _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
