From f7ca82dc00e7f2c657b00d8b0da15429344ea177 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <korli@users.berlios.de>
Date: Tue, 30 Aug 2011 20:46:07 +0000
Subject: [PATCH] Read the previous descriptor pointer before freeing transfer
 and transfer descriptors.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42701 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/busses/usb/ehci.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/add-ons/kernel/busses/usb/ehci.cpp b/src/add-ons/kernel/busses/usb/ehci.cpp
index b8ad5190e7..a5625a7a6a 100644
--- a/src/add-ons/kernel/busses/usb/ehci.cpp
+++ b/src/add-ons/kernel/busses/usb/ehci.cpp
@@ -1758,6 +1758,8 @@ EHCI::FinishIsochronousTransfers()
 
 					transfer->transfer->Finished(B_OK, actualLength);
 
+					itd = itd->prev;
+
 					for (uint32 i = 0; i <= transfer->last_to_process; i++)
 						FreeDescriptor(transfer->descriptors[i]);
 
@@ -1771,8 +1773,8 @@ EHCI::FinishIsochronousTransfers()
 					transferDone = true;
 				} else {
 					TRACE("FinishIsochronousTransfers not end of transfer\n");
+					itd = itd->prev;
 				}
-				itd = itd->prev;
 			}
 
 			UnlockIsochronous();