Hi,all I've meet a problem about reset xhci and it may be caused by the reset order of pci and xhci. Using xhci-pci, when users send reset command in os(centos or red-hat os), it would first reset PCI device by pci_reset_function. During this process, it would disable BME(Bus Master Enable) and set BME=0, and then enable it and set BME=1. And then it comes to xhci reset process. First, it would send an endpoint stop command in xhci_urb_dequeue. However, this stop ep command fails to finish. The reason is that BME is set to 0 in former process and xhci RUN/STOP changes to 0, and when BME is set to 1 again, RUN/STOP doesn't recover to 1. I've checked BME behavior in xhci spec, it shows that "If the BME bit is set to 0 when xHC is running, the xHC may treat this as a Host Controller Error, asserting HCE(1) and immediately halt(R/S=0 and HCH=1). Recovery from this state will require an HCRST." It seems that the stop ep command failure is reasonable. Maybe I've missed something and please let me know. linux version:5.0.0-rc3 Thanks, Nianyao Tang
