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path: root/drivers/usb/host/ehci-q.c
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Diffstat (limited to 'drivers/usb/host/ehci-q.c')
-rw-r--r--drivers/usb/host/ehci-q.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 00ad9ce392e..139a2cc3f64 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,