[PATCH] USB: UHCI: change uhci_explen macro

This patch (as616) changed the uhci_explen macro in uhci-hcd.h so that
it now accepts the desired length, rather than length - 1 with special
handling for 0.  This also fixes a minor bug that would show up only
when a driver submits a 0-length bulk URB.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/uhci-hcd.c

@@ -566,7 +566,7 @@ static int uhci_start(struct usb_hcd *hcd)
 	uhci->skel_bulk_qh->link = cpu_to_le32(uhci->skel_term_qh->dma_handle) | UHCI_PTR_QH;
 
 	/* This dummy TD is to work around a bug in Intel PIIX controllers */
-	uhci_fill_td(uhci->term_td, 0, (UHCI_NULL_DATA_SIZE << 21) |
+	uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
 		(0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
 	uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
 

drivers/usb/host/uhci-hcd.h

@@ -71,8 +71,6 @@
 #define   USBLEGSUP_RWC		0x8f00	/* the R/WC bits */
 #define   USBLEGSUP_RO		0x5040	/* R/O and reserved bits */
 
-#define UHCI_NULL_DATA_SIZE	0x7FF	/* for UHCI controller TD */
-
 #define UHCI_PTR_BITS		cpu_to_le32(0x000F)
 #define UHCI_PTR_TERM		cpu_to_le32(0x0001)
 #define UHCI_PTR_QH		cpu_to_le32(0x0002)
@@ -168,9 +166,11 @@ static __le32 inline qh_element(struct uhci_qh *qh) {
 #define TD_TOKEN_EXPLEN_MASK	0x7FF		/* expected length, encoded as n - 1 */
 #define TD_TOKEN_PID_MASK	0xFF
 
-#define uhci_explen(len)	((len) << TD_TOKEN_EXPLEN_SHIFT)
+#define uhci_explen(len)	((((len) - 1) & TD_TOKEN_EXPLEN_MASK) << \
+					TD_TOKEN_EXPLEN_SHIFT)
 
-#define uhci_expected_length(token) ((((token) >> 21) + 1) & TD_TOKEN_EXPLEN_MASK)
+#define uhci_expected_length(token) ((((token) >> TD_TOKEN_EXPLEN_SHIFT) + \
+					1) & TD_TOKEN_EXPLEN_MASK)
 #define uhci_toggle(token)	(((token) >> TD_TOKEN_TOGGLE_SHIFT) & 1)
 #define uhci_endpoint(token)	(((token) >> 15) & 0xf)
 #define uhci_devaddr(token)	(((token) >> TD_TOKEN_DEVADDR_SHIFT) & 0x7f)

drivers/usb/host/uhci-q.c

@@ -596,7 +596,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
 		return -ENOMEM;
 
 	uhci_add_td_to_urb(urb, td);
-	uhci_fill_td(td, status, destination | uhci_explen(7),
+	uhci_fill_td(td, status, destination | uhci_explen(8),
 		urb->setup_dma);
 
 	/*
@@ -628,7 +628,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
 		destination ^= TD_TOKEN_TOGGLE;
 	
 		uhci_add_td_to_urb(urb, td);
-		uhci_fill_td(td, status, destination | uhci_explen(pktsze - 1),
+		uhci_fill_td(td, status, destination | uhci_explen(pktsze),
 			data);
 
 		data += pktsze;
@@ -658,7 +658,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
 
 	uhci_add_td_to_urb(urb, td);
 	uhci_fill_td(td, status | TD_CTRL_IOC,
-		destination | uhci_explen(UHCI_NULL_DATA_SIZE), 0);
+		destination | uhci_explen(0), 0);
 
 	qh = uhci_alloc_qh(uhci);
 	if (!qh)
@@ -864,7 +864,7 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
 			return -ENOMEM;
 
 		uhci_add_td_to_urb(urb, td);
-		uhci_fill_td(td, status, destination | uhci_explen(pktsze - 1) |
+		uhci_fill_td(td, status, destination | uhci_explen(pktsze) |
 			(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 			 usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
 			data);
@@ -890,7 +890,7 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
 			return -ENOMEM;
 
 		uhci_add_td_to_urb(urb, td);
-		uhci_fill_td(td, status, destination | uhci_explen(UHCI_NULL_DATA_SIZE) |
+		uhci_fill_td(td, status, destination | uhci_explen(0) |
 			(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 			 usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
 			data);
@@ -1092,7 +1092,7 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb)
 			return -ENOMEM;
 
 		uhci_add_td_to_urb(urb, td);
-		uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length - 1),
+		uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length),
 			urb->transfer_dma + urb->iso_frame_desc[i].offset);
 
 		if (i + 1 >= urb->number_of_packets)