Eric W. Biederman wrote: > Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx> writes: > >> Eric W. Biederman wrote: >>> ebiederm@xxxxxxxxxxxx (Eric W. Biederman) writes: >>> >>>> And on the big gotcha's I have found one more I am tracking. >>>> >>>> I am seeing pci bridges with a NULL pointer for the subordinate bus. >>>> Earlier I had thought that this was a symptom of the double remove >>>> but I have been able to reproduce it without that. >>>> >>>> On just a little bit deeper investigation it looks like the cases >>>> are dying are all coming when the nested bridge reappears. >>>> >>>> Which is wrong on so many levels as I am toggle power to the outer >>>> slot, so the nested bridge should not even exist at that time. Ugh. >>>> More tracing to for me on that one. >>> Ok. Got it. I was processing the interrupt for a device after it had >>> been hot removed but before the device state had disappeared. >>> >>> pcie_isr looks like it would be even worse in that situation. Looping forever >>> if pciehp_readw(ctrl, PCIE_EXPSLTA) always succeed sand returns 0xffff. >>> >>> That loop in there appears impossibly misguided. If the pending interrupt >>> values change after you have received the interrupt another instance >>> of the same interrupt should be pending so the loop should be completely >>> unnecessary. >>> >> For level-triggered interrupt, I think it's true. >> >> But for edge-triggered interrupt, I don't think it's true. I think >> only one interrupt is generated if the first hotplug event occurs >> and the second hotplug event occurs before clearing the status of >> first hotplug event. > > My test case is edge-triggered MSI's. The issue is that I get an interrupt > from the card that I am unplugging, but by the time the interrupt handler > is executed the card is physically absent, but the pci_dev structure is > still present in the kernel. > Ok, I understood what is happening. Could you try the following patch? It is currently in Jesse's linux-next. http://marc.info/?l=linux-pci&m=123364118418484&w=2 BTW, I don't think surprise removal is well tested. Thanks, Kenji Kaneshige -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
