Blob Blame Raw
From 7bb437f63758a301ae64ff0ef56b7d107eaa7d99 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Fri, 11 Jul 2014 14:20:58 +0200
Subject: [PATCH 24/43] xhci iso: allow for some latency

Message-id: <1405088470-24115-26-git-send-email-kraxel@redhat.com>
Patchwork-id: 59829
O-Subject: [RHEL-7.1 qemu-kvm PATCH 25/37] xhci iso: allow for some latency
Bugzilla: 949385
RH-Acked-by: Dr. David Alan Gilbert (git) <dgilbert@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

Allow the scheduled transfer time be a bit behind, to
compensate for latencies.  Without this xhci will wait
way to often for the mfindex wraparound, assuming the
scheduled time is in the future just because qemu is
a bit behind in processing the iso transfer requests.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit cc03ff9d0a147a399a11c9f513afa5e06ceee453)
---
 hw/usb/hcd-xhci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/usb/hcd-xhci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 2799539..75da33d 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -1980,7 +1980,7 @@ static void xhci_calc_iso_kick(XHCIState *xhci, XHCITransfer *xfer,
         xfer->mfindex_kick = ((xfer->trbs[0].control >> TRB_TR_FRAMEID_SHIFT)
                               & TRB_TR_FRAMEID_MASK) << 3;
         xfer->mfindex_kick |= mfindex & ~0x3fff;
-        if (xfer->mfindex_kick < mfindex) {
+        if (xfer->mfindex_kick + 0x100 < mfindex) {
             xfer->mfindex_kick += 0x4000;
         }
     }
-- 
1.8.3.1