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FAILED: patch "[PATCH] xhci: don't finish a TD if we get a short transfer event mid" failed to apply to 4.2-stable tree

PATCH [email protected] 1 participant 1 message Nov 6, 2015

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Stable branch USB USB xHCI driver
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The patch below does not apply to the 4.2-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From e210c422b6fdd2dc123bedc588f399aefd8bf9de Mon Sep 17 00:00:00 2001

From: Mathias Nyman <[email protected]>
Date: Mon, 12 Oct 2015 11:30:11 +0300
Subject: [PATCH] xhci: don't finish a TD if we get a short transfer event mid
TD

If the difference is big enough between the bytes asked and received in a bulk transfer we can get a short transfer event pointing to a TRB in the middle of the TD. We don't want to handle the TD yet as we will anyway receive a new event for the last TRB in the TD.

Hold off from finishing the TD and removing it from the list until we receive an event for the last TRB in the TD

Cc stable <[email protected]>
Signed-off-by Mathias Nyman <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/usb/host/xhci-ring.c +10 -0
index 43291f93afeb..79e89e6aef73 100644
@@ -2191,6 +2191,10 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
 		}
 	/* Fast path - was this the last TRB in the TD for this URB? */
 	} else if (event_trb == td->last_trb) {
+		if (td->urb_length_set && trb_comp_code == COMP_SHORT_TX)
+			return finish_td(xhci, td, event_trb, event, ep,
+					 status, false);
+
 		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
 			td->urb->actual_length =
 				td->urb->transfer_buffer_length -

@@ -2242,6 +2246,12 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
 			td->urb->actual_length +=
 				TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
+
+		if (trb_comp_code == COMP_SHORT_TX) {
+			xhci_dbg(xhci, "mid bulk/intr SP, wait for last TRB event\n");
+			td->urb_length_set = true;
+			return 0;
+		}
 	}
 
 	return finish_td(xhci, td, event_trb, event, ep, status, false);