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Diffstat (limited to 'hw/usb/hcd-ohci.c')
-rw-r--r--hw/usb/hcd-ohci.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index c82a92fff7..21c93e0372 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -42,6 +42,8 @@
 
 #define OHCI_MAX_PORTS 15
 
+#define ED_LINK_LIMIT 4
+
 static int64_t usb_frame_time;
 static int64_t usb_bit_time;
 
@@ -725,7 +727,7 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed,
     if (ohci_read_iso_td(ohci, addr, &iso_td)) {
         trace_usb_ohci_iso_td_read_failed(addr);
         ohci_die(ohci);
-        return 0;
+        return 1;
     }
 
     starting_frame = OHCI_BM(iso_td.flags, TD_SF);
@@ -1184,7 +1186,7 @@ static int ohci_service_ed_list(OHCIState *ohci, uint32_t head, int completion)
     uint32_t next_ed;
     uint32_t cur;
     int active;
-
+    uint32_t link_cnt = 0;
     active = 0;
 
     if (head == 0)
@@ -1199,6 +1201,11 @@ static int ohci_service_ed_list(OHCIState *ohci, uint32_t head, int completion)
 
         next_ed = ed.next & OHCI_DPTR_MASK;
 
+        if (++link_cnt > ED_LINK_LIMIT) {
+            ohci_die(ohci);
+            return 0;
+        }
+
         if ((ed.head & OHCI_ED_H) || (ed.flags & OHCI_ED_K)) {
             uint32_t addr;
             /* Cancel pending packets for ED that have been paused.  */