From 955dc88f0c0225985a695689d675e0c119a1bdc4 Mon Sep 17 00:00:00 2001
From: Michael Lotz <mmlr@mlotz.ch>
Date: Sat, 6 Jan 2007 18:05:05 +0000
Subject: [PATCH] * Fixed spinlock usage in EHCI and UHCI drivers * Fixed UHCI
 to allow for empty transfer buffers * Extended the check for still linked
 transfer descriptors when removing a chain

There remain UHCI bugs that will cause transfers outgoing transfers to fail. I'll have to review / rewrite the UHCI driver.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19730 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/busses/usb/ehci.cpp |  2 +-
 src/add-ons/kernel/busses/usb/uhci.cpp | 34 +++++++++++++-------------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/add-ons/kernel/busses/usb/ehci.cpp b/src/add-ons/kernel/busses/usb/ehci.cpp
index 8b3a645dda..d05400712f 100644
--- a/src/add-ons/kernel/busses/usb/ehci.cpp
+++ b/src/add-ons/kernel/busses/usb/ehci.cpp
@@ -762,7 +762,7 @@ EHCI::InterruptHandler(void *data)
 int32
 EHCI::Interrupt()
 {
-	spinlock lock = 0;
+	static spinlock lock = 0;
 	acquire_spinlock(&lock);
 
 	// check if any interrupt was generated
diff --git a/src/add-ons/kernel/busses/usb/uhci.cpp b/src/add-ons/kernel/busses/usb/uhci.cpp
index 0913965f79..c37e6a639d 100644
--- a/src/add-ons/kernel/busses/usb/uhci.cpp
+++ b/src/add-ons/kernel/busses/usb/uhci.cpp
@@ -226,6 +226,8 @@ Queue::AppendDescriptorChain(uhci_td *descriptor)
 
 		element->link_log = descriptor;
 		element->link_phy = descriptor->this_phy | TD_DEPTH_FIRST;
+		if (fQueueHead->element_phy & QH_TERMINATE)
+			fQueueHead->element_phy = descriptor->this_phy;
 		TRACE(("usb_uhci: appended transfer to queue\n"));
 	}
 
@@ -247,11 +249,9 @@ Queue::RemoveDescriptorChain(uhci_td *firstDescriptor, uhci_td *lastDescriptor)
 		if ((lastDescriptor->link_phy & TD_TERMINATE) > 0) {
 			// it is the only chain in this queue
 			fQueueTop = NULL;
-			fQueueHead->element_phy = QH_TERMINATE;
 		} else {
 			// there are still linked transfers
 			fQueueTop = (uhci_td *)lastDescriptor->link_log;
-			fQueueHead->element_phy = fQueueTop->this_phy & TD_LINK_MASK;
 		}
 	} else {
 		// unlink the chain
@@ -265,16 +265,17 @@ Queue::RemoveDescriptorChain(uhci_td *firstDescriptor, uhci_td *lastDescriptor)
 
 			element = (uhci_td *)element->link_log;
 		}
+	}
 
-		element = firstDescriptor;
-		while (element && element != lastDescriptor) {
-			if ((fQueueHead->element_phy & TD_LINK_MASK) == element->this_phy) {
-				fQueueHead->element_phy = lastDescriptor->link_phy;
-				break;
-			}
-
-			element = (uhci_td *)element->link_log;
+	uhci_td *element = firstDescriptor;
+	while (element && element != lastDescriptor->link_log) {
+		if ((fQueueHead->element_phy & TD_LINK_MASK) == element->this_phy) {
+			fQueueHead->element_phy = lastDescriptor->link_phy;
+			TRACE_ERROR(("uhci: queue element pointer still pointing to removed chain\n"));
+			break;
 		}
+
+		element = (uhci_td *)element->link_log;
 	}
 
 	lastDescriptor->link_log = NULL;
@@ -357,8 +358,8 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 		fPCIInfo->function, PCI_command, 2, command);
 
 	// make sure we gain control of the UHCI controller instead of the BIOS
-	sPCIModule->write_pci_config(fPCIInfo->bus, fPCIInfo->device, fPCIInfo->function,
-		PCI_LEGSUP, 2, PCI_LEGSUP_USBPIRQDEN);
+	sPCIModule->write_pci_config(fPCIInfo->bus, fPCIInfo->device,
+		fPCIInfo->function, PCI_LEGSUP, 2, PCI_LEGSUP_USBPIRQDEN);
 
 	// disable interrupts
 	WriteReg16(UHCI_USBINTR, 0);
@@ -523,9 +524,6 @@ UHCI::SubmitTransfer(Transfer *transfer)
 	if (transfer->TransferPipe()->Type() & USB_OBJECT_CONTROL_PIPE)
 		return SubmitRequest(transfer);
 
-	if (transfer->VectorCount() == 0)
-		return B_BAD_VALUE;
-
 	Pipe *pipe = transfer->TransferPipe();
 	bool directionIn = (pipe->Direction() == Pipe::In);
 
@@ -714,7 +712,7 @@ UHCI::AddPendingTransfer(Transfer *transfer, Queue *queue,
 
 	if (fLastTransfer)
 		fLastTransfer->link = data;
-	else
+	if (!fFirstTransfer)
 		fFirstTransfer = data;
 
 	fLastTransfer = data;
@@ -1073,7 +1071,7 @@ UHCI::InterruptHandler(void *data)
 int32
 UHCI::Interrupt()
 {
-	spinlock lock = 0;
+	static spinlock lock = 0;
 	acquire_spinlock(&lock);
 
 	// Check if we really had an interrupt
@@ -1259,6 +1257,8 @@ UHCI::CreateDescriptorChain(Pipe *pipe, uhci_td **_firstDescriptor,
 {
 	size_t packetSize = pipe->MaxPacketSize();
 	int32 descriptorCount = (bufferSize + packetSize - 1) / packetSize;
+	if (descriptorCount == 0)
+		descriptorCount = 1;
 
 	bool dataToggle = pipe->DataToggle();
 	uhci_td *firstDescriptor = NULL;