From 4547897358a12c0f31d688da9922236984742242 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Wed, 29 Aug 2012 10:12:52 +0200
Subject: [PATCH] Revert "ehci: don't flush cache on doorbell rings."

This reverts commit 9bc3a3a216e2689bfcdd36c3e079333bbdbf3ba0, which got
added to fix an issue where the real, underlying cause was not stopping
the ep queue on an error.

Now that the underlying cause is fixed by the "usb: Halt ep queue and
cancel pending packets on a packet error" patch, the "don't flush" fix
is no longer needed.

Not only is it not needed, it causes us to see cancellations (unlinks)
done by the Linux EHCI driver too late, which in combination with the new
usb-core packet-id generation where qtd addresses are used as ids, causes
duplicate ids for in flight packets.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
(cherry picked from commit 66f092d25697e11847b61d761c38ddebedaed8d1)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/usb/hcd-ehci.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 9523247..e7c36f4 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -365,7 +365,6 @@ struct EHCIQueue {
     uint32_t seen;
     uint64_t ts;
     int async;
-    int revalidate;
 
     /* cached data from guest - needs to be flushed
      * when guest removes an entry (doorbell, handshake sequence)
@@ -805,18 +804,7 @@ static EHCIQueue *ehci_find_queue_by_qh(EHCIState *ehci, uint32_t addr,
     return NULL;
 }
 
-static void ehci_queues_tag_unused_async(EHCIState *ehci)
-{
-    EHCIQueue *q;
-
-    QTAILQ_FOREACH(q, &ehci->aqueues, next) {
-        if (!q->seen) {
-            q->revalidate = 1;
-        }
-    }
-}
-
-static void ehci_queues_rip_unused(EHCIState *ehci, int async)
+static void ehci_queues_rip_unused(EHCIState *ehci, int async, int flush)
 {
     EHCIQueueHead *head = async ? &ehci->aqueues : &ehci->pqueues;
     uint64_t maxage = FRAME_TIMER_NS * ehci->maxframes * 4;
@@ -828,7 +816,7 @@ static void ehci_queues_rip_unused(EHCIState *ehci, int async)
             q->ts = ehci->last_run_ns;
             continue;
         }
-        if (ehci->last_run_ns < q->ts + maxage) {
+        if (!flush && ehci->last_run_ns < q->ts + maxage) {
             continue;
         }
         ehci_free_queue(q);
@@ -1684,7 +1672,7 @@ static int ehci_state_waitlisthead(EHCIState *ehci,  int async)
         ehci_set_usbsts(ehci, USBSTS_REC);
     }
 
-    ehci_queues_rip_unused(ehci, async);
+    ehci_queues_rip_unused(ehci, async, 0);
 
     /*  Find the head of the list (4.9.1.1) */
     for(i = 0; i < MAX_QH; i++) {
@@ -1769,7 +1757,6 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
     EHCIPacket *p;
     uint32_t entry, devaddr;
     EHCIQueue *q;
-    EHCIqh qh;
 
     entry = ehci_get_fetch_addr(ehci, async);
     q = ehci_find_queue_by_qh(ehci, entry, async);
@@ -1787,17 +1774,7 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
     }
 
     get_dwords(ehci, NLPTR_GET(q->qhaddr),
-               (uint32_t *) &qh, sizeof(EHCIqh) >> 2);
-    if (q->revalidate && (q->qh.epchar      != qh.epchar ||
-                          q->qh.epcap       != qh.epcap  ||
-                          q->qh.current_qtd != qh.current_qtd)) {
-        ehci_free_queue(q);
-        q = ehci_alloc_queue(ehci, entry, async);
-        q->seen++;
-        p = NULL;
-    }
-    q->qh = qh;
-    q->revalidate = 0;
+               (uint32_t *) &q->qh, sizeof(EHCIqh) >> 2);
     ehci_trace_qh(q, NLPTR_GET(q->qhaddr), &q->qh);
 
     devaddr = get_field(q->qh.epchar, QH_EPCHAR_DEVADDR);
@@ -2306,7 +2283,7 @@ static void ehci_advance_async_state(EHCIState *ehci)
          */
         if (ehci->usbcmd & USBCMD_IAAD) {
             /* Remove all unseen qhs from the async qhs queue */
-            ehci_queues_tag_unused_async(ehci);
+            ehci_queues_rip_unused(ehci, async, 1);
             DPRINTF("ASYNC: doorbell request acknowledged\n");
             ehci->usbcmd &= ~USBCMD_IAAD;
             ehci_raise_irq(ehci, USBSTS_IAA);
@@ -2359,7 +2336,7 @@ static void ehci_advance_periodic_state(EHCIState *ehci)
         ehci_set_fetch_addr(ehci, async,entry);
         ehci_set_state(ehci, async, EST_FETCHENTRY);
         ehci_advance_state(ehci, async);
-        ehci_queues_rip_unused(ehci, async);
+        ehci_queues_rip_unused(ehci, async, 0);
         break;
 
     default:
-- 
1.7.12.1