Patchwork [16/26] uhci: Maximize how many frames we catch up when behind

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Submitter Hans de Goede
Date Dec. 14, 2012, 1:35 p.m.
Message ID <1355492147-5023-17-git-send-email-hdegoede@redhat.com>
Download mbox | patch
Permalink /patch/206479/
State New
Headers show

Comments

Hans de Goede - Dec. 14, 2012, 1:35 p.m.
If somehow we've gotten behind a lot, simply skip ahead, like the ehci code
does.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-uhci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index 2a5d4cc..fa75a77 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -171,6 +171,7 @@  struct UHCIState {
     /* Properties */
     char *masterbus;
     uint32_t firstport;
+    uint32_t maxframes;
 };
 
 typedef struct UHCI_TD {
@@ -1201,6 +1202,12 @@  static void uhci_frame_timer(void *opaque)
 
     /* Process up to MAX_FRAMES_PER_TICK frames */
     frames = (t_now - t_last_run) / frame_t;
+    if (frames > s->maxframes) {
+        int skipped = frames - s->maxframes;
+        s->expire_time += skipped * frame_t;
+        s->frnum = (s->frnum + skipped) & 0x7ff;
+        frames -= skipped;
+    }
     if (frames > MAX_FRAMES_PER_TICK) {
         frames = MAX_FRAMES_PER_TICK;
     }
@@ -1326,6 +1333,7 @@  static Property uhci_properties[] = {
     DEFINE_PROP_STRING("masterbus", UHCIState, masterbus),
     DEFINE_PROP_UINT32("firstport", UHCIState, firstport, 0),
     DEFINE_PROP_UINT32("bandwidth", UHCIState, frame_bandwidth, 1280),
+    DEFINE_PROP_UINT32("maxframes", UHCIState, maxframes, 128),
     DEFINE_PROP_END_OF_LIST(),
 };