From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 21 Mar 2012 17:25:25 +0000 (+0100)
Subject: usb-uhci: stop queue filling when we find a in-flight td
X-Git-Tag: v1.1-rc0~91^2~19
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=52b0fecdba217e02d7e7eef975d942b153950b2f;p=thirdparty%2Fqemu.git

usb-uhci: stop queue filling when we find a in-flight td

Not only QHs can form rings, but TDs too.  With the new
queuing/pipelining support we are following TD chains and
can actually walk in circles.  An assert() prevents us from
entering an endless loop then.

Fix is easy:  Just stop queuing when we figure the TD we are
about to queue up is in flight already.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---

diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index e55dad914c3..2be564b6759 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -965,6 +965,9 @@ static void uhci_fill_queue(UHCIState *s, UHCI_TD *td)
         }
         trace_usb_uhci_td_queue(plink & ~0xf, ptd.ctrl, ptd.token);
         ret = uhci_handle_td(s, plink, &ptd, &int_mask);
+        if (ret == TD_RESULT_ASYNC_CONT) {
+            break;
+        }
         assert(ret == TD_RESULT_ASYNC_START);
         assert(int_mask == 0);
         plink = ptd.link;