diff options
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index a5ba5ace3d00..aec69d294973 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -5079,11 +5079,18 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks) hcd->has_tt = 1; } else { /* - * Some 3.1 hosts return sbrn 0x30, use xhci supported protocol - * minor revision instead of sbrn. Minor revision is a two digit - * BCD containing minor and sub-minor numbers, only show minor. + * Early xHCI 1.1 spec did not mention USB 3.1 capable hosts + * should return 0x31 for sbrn, or that the minor revision + * is a two digit BCD containig minor and sub-minor numbers. + * This was later clarified in xHCI 1.2. + * + * Some USB 3.1 capable hosts therefore have sbrn 0x30, and + * minor revision set to 0x1 instead of 0x10. */ - minor_rev = xhci->usb3_rhub.min_rev / 0x10; + if (xhci->usb3_rhub.min_rev == 0x1) + minor_rev = 1; + else + minor_rev = xhci->usb3_rhub.min_rev / 0x10; switch (minor_rev) { case 2: |