4 files changed, 18 insertions, 1 deletions
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
index 3fcb0f9914..a3eb14b28c 100644..100755
--- a/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/Ehci.c
@@ -1095,6 +1095,12 @@ EhcAsyncInterruptTransfer (
   EhcLinkQhToPeriod (Ehc, Urb->Qh);
   InsertHeadList (&Ehc->AsyncIntTransfers, &Urb->UrbList);
 
+  // ARM: Force an asynchonous transfer after waiting an interval
+  //      Polling interval is in milliseconds while BS.Stall except
+  //      Microseconds.
+  gBS->Stall (PollingInterval * 1000);
+  EhcMonitorAsyncRequests (Ehc->PollTimer, Ehc);
+
 ON_EXIT:
   Ehc->PciIo->Flush (Ehc->PciIo);
   gBS->RestoreTPL (OldTpl);
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
index 5594e6699e..cc6e77e385 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
@@ -573,6 +573,12 @@ EhcCheckUrbResult (
 
   ASSERT ((Ehc != NULL) && (Urb != NULL) && (Urb->Qh != NULL));
 
+  // The URB is already being processed, we do not want the callback to be
+  // called twice for the same URB
+  if (Urb->InProgress) {
+    return FALSE;
+  }
+
   Finished        = TRUE;
   Urb->Completed  = 0;
 
@@ -992,6 +998,9 @@ EhcMonitorAsyncRequests (
       continue;
     }
 
+    // Mark the URB as 'in-progress' to prevent the URB to be processed twice.
+    Urb->InProgress = TRUE;
+
     //
     // Flush any PCI posted write transactions from a PCI host
     // bridge to system memory.
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.c b/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.c
index 6afb327df1..1ad37d5bd1 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.c
@@ -600,6 +600,7 @@ EhcCreateUrb (
   Urb->DataLen    = DataLen;
   Urb->Callback   = Callback;
   Urb->Context    = Context;
+  Urb->InProgress = FALSE;
 
   PciIo           = Ehc->PciIo;
   Urb->Qh         = EhcCreateQh (Ehc, &Urb->Ep);
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.h b/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.h
index 02e9af81be..0c80e76248 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.h
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciUrb.h
@@ -232,7 +232,8 @@ struct _URB {
   // Transaction result
   //
   UINT32                          Result;
-  UINTN                           Completed;    // completed data length
+  BOOLEAN                         InProgress;   // defined when the URB is being processed
+  UINTN                           Completed;    // Length of the data being processed
   UINT8                           DataToggle;
 };