Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: 85251960f51165153a99151c090c85351220aab0 ("USB: hub.c: decrease the number of attempts of enumeration scheme")
url: https://github.com/0day-ci/linux/commits/UPDATE-20200813-011035/Yasushi-Asano/USB-hub-c-decrease-the-number-of-attempts-of-enumeration-scheme/20200808-144104


in testcase: suspend-stress
with following parameters:

	mode: mem
	iterations: 10



on test machine: 4 threads Ivy Bridge with 4G memory

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):




If you fix the issue, kindly add following tag
Reported-by: kernel test robot <rong.a.chen@intel.com>


kern  :info  : [   69.109673] usb 1-1.3: new high-speed USB device number 14 using ehci-pci
kern  :info  : [   69.112670] usb 2-1.5: new full-speed USB device number 11 using ehci-pci
kern  :err   : [   69.114646] usb 2-1.5: Invalid ep0 maxpacket: 0
kern  :info  : [   69.181755] usb 2-1.5: new full-speed USB device number 12 using ehci-pci
kern  :err   : [   69.183234] usb 2-1.5: Invalid ep0 maxpacket: 0
kern  :info  : [   69.186746] usb 2-1-port5: attempt power cycle
kern  :err   : [   69.273841] usb 1-1.3: Invalid ep0 maxpacket: 0
kern  :info  : [   69.341750] usb 1-1.3: new high-speed USB device number 15 using ehci-pci
kern  :err   : [   69.346911] usb 1-1.3: Invalid ep0 maxpacket: 0
kern  :info  : [   69.350748] usb 1-1-port3: attempt power cycle
kern  :info  : [   69.764750] usb 2-1.5: new full-speed USB device number 13 using ehci-pci
kern  :info  : [   69.932768] usb 1-1.3: new high-speed USB device number 16 using ehci-pci
kern  :info  : [   69.993350] usb 2-1.5: New USB device found, idVendor=08ff, idProduct=168b, bcdDevice=25.01
kern  :info  : [   69.994512] usb 2-1.5: New USB device strings: Mfr=0, Product=1, SerialNumber=0
kern  :info  : [   69.995625] usb 2-1.5: Product: Fingerprint Sensor
kern  :info  : [   70.321507] usb 1-1.3: New USB device found, idVendor=1bcf, idProduct=288e, bcdDevice=18.09
kern  :info  : [   70.323134] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
kern  :info  : [   70.324729] usb 1-1.3: Product: TOSHIBA Web Camera - HD
kern  :info  : [   70.326186] usb 1-1.3: Manufacturer: C7C7M6A5



To reproduce:

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp install job.yaml  # job file is attached in this email
        bin/lkp run     job.yaml



Thanks,
Rong Chen