On Wed, May 05, 2021 at 02:33:46PM +0200, Pali Rohár wrote: > I just spotted this crash during debugging PCIe controller driver > pci-aardvark.c with trying to expose its link down events via "hot plug" > interrupt and corresponding link layer state flags. > > And because in whole call trace I see only generic PCIe and USB code > path without any driver specific parts, I suspect that this is not PCIe > controller-specific issue but rather something "wrong" in genetic PCIe > (or USB) code. That is why I sent this email, so maybe somebody else > find something suspicious here. > > But still there is a chance that issue can be also in pci-aardvark.c > driver and somehow it masked its issue and propagated it into generic > PCIe hot plug code path. If you hot-remove the XHCI controller, accesses to its MMIO space will fail. xhci_irq() seems to perform such MMIO accesses. Normally this should happen silently and MMIO accesses just return with a fabricated "all ones" response. Chances are however that the Aardvark controller raises a synchronous external abort instead. Perhaps you can teach it not to do that. Thanks, Lukas
