[U-Boot] Crash upon loading from non-existent USB device

[Stefan Roese]

Hi,

I'm currently testing v2017.11 on my x86 platform using
the xHCI interface to load images via USB keys. But if
I don't have any USB key installed, U-Boot crashes:

=> usb reset
resetting USB...
USB0:   Register 7000820 NbrPorts 7
Starting the controller
USB XHCI 1.00
scanning bus 0 for devices... 4 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
=> load usb 0:1 03000000 abc
General Protection
EIP: 0010:[<7b59030d>] EFLAGS: 00010286
Original EIP :[<fff4330d>]
EAX: ffffffff EBX: 7b3556d0 ECX: 00000001 EDX: 00000000
ESI: 00000000 EDI: 00000001 EBP: 7b356430 ESP: 7b336efc
 DS: 0018 ES: 0018 FS: 0020 GS: 0018 SS: 0018
CR0: 00000033 CR2: 00000000 CR3: 00000000 CR4: 00000600
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Stack:
    0x7b336f3c : 0x00000000
    0x7b336f38 : 0x00000000
    0x7b336f34 : 0x00000000
    0x7b336f30 : 0x00000000
    0x7b336f2c : 0x00000000
    0x7b336f28 : 0x00000000
    0x7b336f24 : 0x00000000
    0x7b336f20 : 0x00000000
    0x7b336f1c : 0x00000000
    0x7b336f18 : 0x00000000
    0x7b336f14 : 0x00000000
    0x7b336f10 : 0x7b3556c8
    0x7b336f0c : 0x7b554420
    0x7b336f08 : 0x7b336f20
    0x7b336f04 : 0x7b356420
    0x7b336f00 : 0x7b3556d0
--->0x7b336efc : 0x7b590507
    0x7b336ef8 : 0x00010286
    0x7b336ef4 : 0x00000010
    0x7b336ef0 : 0x7b59030d
### ERROR ### Please RESET the board ###

Using v2017.09 this problem does not occur:

=> usb start
starting USB...
USB0:   Register 7000820 NbrPorts 7
Starting the controller
USB XHCI 1.00
scanning bus 0 for devices... 4 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
=> load usb 0:1 03000000 abc
** Bad device usb 0 **


Does anyone have a quick idea, which commit might have
introduced this regression?

Thanks,
Stefan