From 5f92e39f7b50cd57fffbdde384133052c749f7bd Mon Sep 17 00:00:00 2001
From: Michael Lotz <mmlr@mlotz.ch>
Date: Thu, 20 Aug 2009 04:45:13 +0000
Subject: [PATCH] That's actually not how it works. OHCI does the dirty work of
 splitting up the transfer descriptors into individual packets. The
 descriptors are more a logical thing. As such we do not generate one
 descriptor per packet but one for each block of two pages at max. Therefore
 we only set the initial toggle bit to the one we stored on the first
 descriptor and let OHCI use the carry bit for subsequet descriptors. That
 error would only be visible on transfers above two pages in size though.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32532 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/busses/usb/ohci.cpp | 23 ++++++++++++-----------
 src/add-ons/kernel/busses/usb/ohci.h   |  2 +-
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/add-ons/kernel/busses/usb/ohci.cpp b/src/add-ons/kernel/busses/usb/ohci.cpp
index bcb74ff48d..ad6130e9b0 100644
--- a/src/add-ons/kernel/busses/usb/ohci.cpp
+++ b/src/add-ons/kernel/busses/usb/ohci.cpp
@@ -962,7 +962,7 @@ OHCI::_FinishTransfers()
 					}
 				}
 
-				// the td has complete without an error
+				// the td has completed without an error
 				TRACE("td %p done\n", descriptor);
 
 				if (descriptor == transfer->last_descriptor
@@ -1114,9 +1114,8 @@ OHCI::_SubmitRequest(Transfer *transfer)
 	ohci_general_td *dataDescriptor = NULL;
 	if (transfer->VectorCount() > 0) {
 		ohci_general_td *lastDescriptor = NULL;
-		result = _CreateDescriptorChain(transfer->TransferPipe(),
-			&dataDescriptor, &lastDescriptor, directionIn
-				? OHCI_TD_DIRECTION_PID_IN : OHCI_TD_DIRECTION_PID_OUT,
+		result = _CreateDescriptorChain(&dataDescriptor, &lastDescriptor,
+			directionIn ? OHCI_TD_DIRECTION_PID_IN : OHCI_TD_DIRECTION_PID_OUT,
 			transfer->VectorLength());
 		if (result < B_OK) {
 			_FreeGeneralDescriptor(setupDescriptor);
@@ -1164,14 +1163,18 @@ OHCI::_SubmitTransfer(Transfer *transfer)
 
 	ohci_general_td *firstDescriptor = NULL;
 	ohci_general_td *lastDescriptor = NULL;
-	status_t result = _CreateDescriptorChain(pipe, &firstDescriptor,
-		&lastDescriptor, directionIn
-			? OHCI_TD_DIRECTION_PID_IN : OHCI_TD_DIRECTION_PID_OUT,
+	status_t result = _CreateDescriptorChain(&firstDescriptor, &lastDescriptor,
+		directionIn ? OHCI_TD_DIRECTION_PID_IN : OHCI_TD_DIRECTION_PID_OUT,
 		transfer->VectorLength());
 
 	if (result < B_OK)
 		return result;
 
+	// Apply data toggle to the first descriptor (the others will use the carry)
+	firstDescriptor->flags &= ~OHCI_TD_TOGGLE_CARRY;
+	firstDescriptor->flags |= pipe->DataToggle() ? OHCI_TD_TOGGLE_1
+		: OHCI_TD_TOGGLE_0;
+
 	// Set the last descriptor to generate an interrupt
 	lastDescriptor->flags &= ~OHCI_TD_INTERRUPT_MASK;
 	lastDescriptor->flags |=
@@ -1521,7 +1524,7 @@ OHCI::_FreeGeneralDescriptor(ohci_general_td *descriptor)
 
 
 status_t
-OHCI::_CreateDescriptorChain(Pipe *pipe, ohci_general_td **_firstDescriptor,
+OHCI::_CreateDescriptorChain(ohci_general_td **_firstDescriptor,
 	ohci_general_td **_lastDescriptor, uint32 direction, size_t bufferSize)
 {
 	size_t blockSize = 8192;
@@ -1529,7 +1532,6 @@ OHCI::_CreateDescriptorChain(Pipe *pipe, ohci_general_td **_firstDescriptor,
 	if (descriptorCount == 0)
 		descriptorCount = 1;
 
-	bool dataToggle = pipe->DataToggle();
 	ohci_general_td *firstDescriptor = NULL;
 	ohci_general_td *lastDescriptor = *_firstDescriptor;
 	for (int32 i = 0; i < descriptorCount; i++) {
@@ -1545,13 +1547,12 @@ OHCI::_CreateDescriptorChain(Pipe *pipe, ohci_general_td **_firstDescriptor,
 			| OHCI_TD_BUFFER_ROUNDING
 			| OHCI_TD_SET_CONDITION_CODE(OHCI_TD_CONDITION_NOT_ACCESSED)
 			| OHCI_TD_SET_DELAY_INTERRUPT(OHCI_TD_INTERRUPT_NONE)
-			| (dataToggle ? OHCI_TD_TOGGLE_1 : OHCI_TD_TOGGLE_0);		
+			| OHCI_TD_TOGGLE_CARRY;		
 
 		// link to previous
 		if (lastDescriptor)
 			_LinkDescriptors(lastDescriptor, descriptor);
 
-		dataToggle = !dataToggle;
 		bufferSize -= blockSize;
 		lastDescriptor = descriptor;
 		if (!firstDescriptor)
diff --git a/src/add-ons/kernel/busses/usb/ohci.h b/src/add-ons/kernel/busses/usb/ohci.h
index 97a31ff973..b23ce6f46e 100644
--- a/src/add-ons/kernel/busses/usb/ohci.h
+++ b/src/add-ons/kernel/busses/usb/ohci.h
@@ -101,7 +101,7 @@ static	int32						_FinishThread(void *data);
 		void						_FreeGeneralDescriptor(
 										ohci_general_td *descriptor);
 
-		status_t					_CreateDescriptorChain(Pipe *pipe,
+		status_t					_CreateDescriptorChain(
 										ohci_general_td **firstDescriptor,
 										ohci_general_td **lastDescriptor,
 										uint32 direction,