On Wed, 2018-08-15 at 14:16 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2018-08-15 at 13:35 +1000, Benjamin Herrenschmidt wrote: > > What's really needed is a per device mutex covering all those operations > > on a given device. (This would also allow to get rid of those games with > > atomics). > > > > Any comments ? > > Note: I'm experienting with a per-pci_dev mutex to protect the device > state. If it works out, I suggest we add it, then progressively > move things one by one under the protection of the mutex. > > Any objection to the approach ? If it fixes my problem, I'll send > preliminary patches that cover the basic enable/disable and bus > master settings to start with. We should try to get them into > stable as this is breaking real world stuff for us. > > I suspect large x86 systems get lucky because their BIOSes do all > the enables. It would be possible to reproduce the races there by > hot-pluging a large external drawer using a cable card with a switch BTW. Should we plan a PCIe microconf for Plumbers ? Cheers, Ben.
