Thank you Greg, So it seems xhci's interrupt based on it's rx/tx queue(ring), the ring is shared by all USB device, it is not aware of "per USB device"? Regards Yunhua On Fri, Jul 5, 2019 at 9:46 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Fri, Jul 05, 2019 at 07:50:28PM -0700, yunhua li wrote: > > Hi all > > > > xhci_msi_irq is the interrupt handler for xhci, the controller it self > > is a PCI device, on my system it is a Intel chip. I have multiple USB > > device connect to this USB host controller, xhci_msi_irq is interrupt > > handler for the PCI device(USB Host controller). > > Is it possible to have multiple IRQ, and different IRQ for different > > USB device? > > Nope. That is not how USB works. Please read the xhci spec if you are > curious as to why. > > greg k-h
