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-rw-r--r--hw/usb-uhci.c29
1 files changed, 22 insertions, 7 deletions
diff --git a/hw/usb-uhci.c b/hw/usb-uhci.c
index cddcc8927a..e0c7dbb71a 100644
--- a/hw/usb-uhci.c
+++ b/hw/usb-uhci.c
@@ -73,7 +73,7 @@
#define FRAME_TIMER_FREQ 1000
-#define FRAME_MAX_LOOPS 100
+#define FRAME_MAX_LOOPS 256
#define NB_PORTS 2
@@ -942,7 +942,7 @@ static int qhdb_insert(QhDb *db, uint32_t addr)
static void uhci_process_frame(UHCIState *s)
{
uint32_t frame_addr, link, old_td_ctrl, val, int_mask;
- uint32_t curr_qh;
+ uint32_t curr_qh, td_count = 0, bytes_count = 0;
int cnt, ret;
UHCI_TD td;
UHCI_QH qh;
@@ -967,13 +967,26 @@ static void uhci_process_frame(UHCIState *s)
if (qhdb_insert(&qhdb, link)) {
/*
* We're going in circles. Which is not a bug because
- * HCD is allowed to do that as part of the BW management.
- * In our case though it makes no sense to spin here. Sync transations
- * are already done, and async completion handler will re-process
- * the frame when something is ready.
+ * HCD is allowed to do that as part of the BW management.
+ *
+ * Stop processing here if
+ * (a) no transaction has been done since we've been
+ * here last time, or
+ * (b) we've reached the usb 1.1 bandwidth, which is
+ * 1280 bytes/frame.
*/
DPRINTF("uhci: detected loop. qh 0x%x\n", link);
- break;
+ if (td_count == 0) {
+ DPRINTF("uhci: no transaction last round, stop\n");
+ break;
+ } else if (bytes_count >= 1280) {
+ DPRINTF("uhci: bandwidth limit reached, stop\n");
+ break;
+ } else {
+ td_count = 0;
+ qhdb_reset(&qhdb);
+ qhdb_insert(&qhdb, link);
+ }
}
pci_dma_read(&s->dev, link & ~0xf, &qh, sizeof(qh));
@@ -1033,6 +1046,8 @@ static void uhci_process_frame(UHCIState *s)
link, td.link, td.ctrl, td.token, curr_qh);
link = td.link;
+ td_count++;
+ bytes_count += (td.ctrl & 0x7ff) + 1;
if (curr_qh) {
/* update QH element link */