USB: Use (get|put)_unaligned for accessing wMaxPacketSize

In 9792987721c7980453fe6447c3fa6593b44f8458 Stefan describes a usecase
where the previous behavior of leaving wMaxPacketSize be unaligned
caused fatal problems.  The initial fix for this problem was incomplete
however as it showed another cases of non-aligned access that previously
worked implicitly.  This switches to making sure that all access of
wMaxPacketSize are done via (get|put)_unaligned.

In order to maintain a level of readability to the code in some cases
we now use a variable for the value of wMaxPacketSize and in others, a
macro.

Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Remy Bohmer <linux@bohmer.net>

OpenRISC:
Tested-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>

Beagleboard xM, Pandaboard run-tested, s5p_goni build-tested.
Signed-off-by: Tom Rini <trini@ti.com>

2 files changed, 21 insertions, 9 deletions

diff --git a/common/cmd_usb.c b/common/cmd_usb.c
index d4ec2a2..320667f 100644
--- a/common/cmd_usb.c
+++ b/common/cmd_usb.c
@@ -28,6 +28,7 @@
 #include <common.h>
 #include <command.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 #include <part.h>
 #include <usb.h>
 
@@ -240,7 +241,7 @@ void usb_display_ep_desc(struct usb_endpoint_descriptor *epdesc)
 		printf("Interrupt");
 		break;
 	}
-	printf(" MaxPacket %d", epdesc->wMaxPacketSize);
+	printf(" MaxPacket %d", get_unaligned(&epdesc->wMaxPacketSize));
 	if ((epdesc->bmAttributes & 0x03) == 0x3)
 		printf(" Interval %dms", epdesc->bInterval);
 	printf("\n");
diff --git a/common/usb.c b/common/usb.c
index 4418c70..63a11c8 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -49,6 +49,7 @@
 #include <asm/processor.h>
 #include <linux/ctype.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 
 #include <usb.h>
 #ifdef CONFIG_4xx
@@ -279,30 +280,32 @@ usb_set_maxpacket_ep(struct usb_device *dev, int if_idx, int ep_idx)
 {
 	int b;
 	struct usb_endpoint_descriptor *ep;
+	u16 ep_wMaxPacketSize;
 
 	ep = &dev->config.if_desc[if_idx].ep_desc[ep_idx];
 
 	b = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
+	ep_wMaxPacketSize = get_unaligned(&ep->wMaxPacketSize);
 
 	if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 						USB_ENDPOINT_XFER_CONTROL) {
 		/* Control => bidirectional */
-		dev->epmaxpacketout[b] = ep->wMaxPacketSize;
-		dev->epmaxpacketin[b] = ep->wMaxPacketSize;
+		dev->epmaxpacketout[b] = ep_wMaxPacketSize;
+		dev->epmaxpacketin[b] = ep_wMaxPacketSize;
 		USB_PRINTF("##Control EP epmaxpacketout/in[%d] = %d\n",
 			   b, dev->epmaxpacketin[b]);
 	} else {
 		if ((ep->bEndpointAddress & 0x80) == 0) {
 			/* OUT Endpoint */
-			if (ep->wMaxPacketSize > dev->epmaxpacketout[b]) {
-				dev->epmaxpacketout[b] = ep->wMaxPacketSize;
+			if (ep_wMaxPacketSize > dev->epmaxpacketout[b]) {
+				dev->epmaxpacketout[b] = ep_wMaxPacketSize;
 				USB_PRINTF("##EP epmaxpacketout[%d] = %d\n",
 					   b, dev->epmaxpacketout[b]);
 			}
 		} else {
 			/* IN Endpoint */
-			if (ep->wMaxPacketSize > dev->epmaxpacketin[b]) {
-				dev->epmaxpacketin[b] = ep->wMaxPacketSize;
+			if (ep_wMaxPacketSize > dev->epmaxpacketin[b]) {
+				dev->epmaxpacketin[b] = ep_wMaxPacketSize;
 				USB_PRINTF("##EP epmaxpacketin[%d] = %d\n",
 					   b, dev->epmaxpacketin[b]);
 			}
@@ -333,6 +336,7 @@ int usb_parse_config(struct usb_device *dev, unsigned char *buffer, int cfgno)
 	struct usb_descriptor_header *head;
 	int index, ifno, epno, curr_if_num;
 	int i;
+	u16 ep_wMaxPacketSize;
 
 	ifno = -1;
 	epno = -1;
@@ -378,8 +382,15 @@ int usb_parse_config(struct usb_device *dev, unsigned char *buffer, int cfgno)
 			dev->config.if_desc[ifno].no_of_ep++;
 			memcpy(&dev->config.if_desc[ifno].ep_desc[epno],
 				&buffer[index], buffer[index]);
-			le16_to_cpus(&(dev->config.if_desc[ifno].ep_desc[epno].\
-							       wMaxPacketSize));
+			ep_wMaxPacketSize = get_unaligned(&dev->config.\
+							if_desc[ifno].\
+							ep_desc[epno].\
+							wMaxPacketSize);
+			put_unaligned(le16_to_cpu(ep_wMaxPacketSize),
+					&dev->config.\
+					if_desc[ifno].\
+					ep_desc[epno].\
+					wMaxPacketSize);
 			USB_PRINTF("if %d, ep %d\n", ifno, epno);
 			break;
 		default: