add comments to clarify the enhancement on EHCI driver, which is guaranteed to get...

[mirror_edk2.git] / MdeModulePkg / Bus / Pci / EhciDxe / EhciDxe.inf

diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciDxe.inf b/MdeModulePkg/Bus/Pci/EhciDxe/EhciDxe.inf
index fd98e4200f007e4f6179d74f4b6624b1e85e3859..381f4bd4004db70e93b18296ac3387db7c73f11b 100644 (file)
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciDxe.inf
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciDxe.inf
@@ -6,6 +6,11 @@
 #  It implements the interfaces of monitoring the status of all ports and transferring \r
 #  Control, Bulk, Interrupt and Isochronous requests to Usb2.0 device.\r
 #\r
+#  Note that EhciDxe driver is enhanced to guarantee that the EHCI controller get attached\r
+#  to the EHCI controller before the UHCI driver attaches to the companion UHCI controller. \r
+#  This way avoids the control transfer on a shared port between EHCI and companion host\r
+#  controller when UHCI gets attached earlier than EHCI and a USB 2.0 device inserts.\r
+#\r
 #  Copyright (c) 2006 - 2009, Intel Corporation. \r
 #\r
 #  All rights reserved. This program and the accompanying materials\r