On Tue, Jun 06, 2017 at 04:14:43PM -0500, Bjorn Helgaas wrote: > So I guess the method here is > dev->driver->err_handler->reset_notify(), and the PCI core should be > holding device_lock() while calling it? That makes sense to me; > thanks a lot for articulating that! Yes. > 1) The current patch protects the err_handler->reset_notify() uses by > adding or expanding device_lock regions in the paths that lead to > pci_reset_notify(). Could we simplify it by doing the locking > directly in pci_reset_notify()? Then it would be easy to verify the > locking, and we would be less likely to add new callers without the > proper locking. We could do that, except that I'd rather hold the lock over a longer period if we have many calls following each other. I also have a patch to actually kill pci_reset_notify() later in the series as well, as the calling convention for it and ->reset_notify() are awkward - depending on prepare parameter they do two entirely different things. That being said I could also add new pci_reset_prepare() and pci_reset_done() helpers. > 2) Stating the rule explicitly helps look for other problems, and I > think we have a similar problem in all the pcie_portdrv_err_handler > methods. Yes, I mentioned this earlier, and I also vaguely remember we got bug reports from IBM on power for this a while ago. I just don't feel confident enough to touch all these without a good test plan.
