diff options
Diffstat (limited to 'drivers/usb/host/ehci-q.c')
| -rw-r--r-- | drivers/usb/host/ehci-q.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 00ad9ce392ed..139a2cc3f641 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -487,8 +487,20 @@ halt: * we must clear the TT buffer (11.17.5). */ if (unlikely(last_status != -EINPROGRESS && - last_status != -EREMOTEIO)) - ehci_clear_tt_buffer(ehci, qh, urb, token); + last_status != -EREMOTEIO)) { + /* The TT's in some hubs malfunction when they + * receive this request following a STALL (they + * stop sending isochronous packets). Since a + * STALL can't leave the TT buffer in a busy + * state (if you believe Figures 11-48 - 11-51 + * in the USB 2.0 spec), we won't clear the TT + * buffer in this case. Strictly speaking this + * is a violation of the spec. + */ + if (last_status != -EPIPE) + ehci_clear_tt_buffer(ehci, qh, urb, + token); + } } /* if we're removing something not at the queue head, |