Patchwork [04/22] ehci: Set int flag on a short input packet

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Submitter Hans de Goede
Date Oct. 15, 2012, 10:38 a.m.
Message ID <1350297511-25437-5-git-send-email-hdegoede@redhat.com>
Download mbox | patch
Permalink /patch/191522/
State New
Headers show

Comments

Hans de Goede - Oct. 15, 2012, 10:38 a.m.
According to 4.15.1.2 an interrupt must be raised when a short packet
is received. If we don't do this it may take a significant time for
the guest to notice a short trasnfer has completed, since only the last td
will have its IOC flag set, and a short transfer may complete in an earlier
packet.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-ehci.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 6945992..d9d4918 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -1508,6 +1508,10 @@  static void ehci_execute_complete(EHCIQueue *q)
 
         if (tbytes && p->pid == USB_TOKEN_IN) {
             tbytes -= p->usb_status;
+            if (tbytes) {
+                /* 4.15.1.2 must raise int on a short input packet */
+                ehci_raise_irq(q->ehci, USBSTS_INT);
+            }
         } else {
             tbytes = 0;
         }