[Qemu-devel] [PATCH 09/54] ehci: Properly report completed but not yet processed packets to the guest

[Gerd Hoffmann]

From: Hans de Goede <address@hidden>

Reported packets which have completed before being cancelled as such to the
host. Note that the new code path this patch adds is untested since it I've
been unable to actually trigger the race which needs this code path.

Signed-off-by: Hans de Goede <address@hidden>
---
 hw/usb/hcd-ehci.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 4fe85c8..0a6c9ef 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -489,6 +489,9 @@ static const char *ehci_mmio_names[] = {
     [CONFIGFLAG]        = "CONFIGFLAG",
 };
 
+static int ehci_state_executing(EHCIQueue *q);
+static int ehci_state_writeback(EHCIQueue *q);
+
 static const char *nr2str(const char **n, size_t len, uint32_t nr)
 {
     if (nr < len && n[nr] != NULL) {
@@ -750,6 +753,16 @@ static void ehci_free_packet(EHCIPacket *p)
         usb_packet_unmap(&p->packet, &p->sgl);
         qemu_sglist_destroy(&p->sgl);
     }
+    if (p->async == EHCI_ASYNC_FINISHED) {
+        int state = ehci_get_state(p->queue->ehci, p->queue->async);
+        /* This is a normal, but rare condition (cancel racing completion) */
+        fprintf(stderr, "EHCI: Warning packet completed but not processed\n");
+        ehci_state_executing(p->queue);
+        ehci_state_writeback(p->queue);
+        ehci_set_state(p->queue->ehci, p->queue->async, state);
+        /* state_writeback recurses into us with async == EHCI_ASYNC_NONE!! */
+        return;
+    }
     QTAILQ_REMOVE(&p->queue->packets, p, next);
     usb_packet_cleanup(&p->packet);
     g_free(p);
-- 
1.7.1