From 0bbc8c5421bea9062a7c8db102b635d24984a612 Mon Sep 17 00:00:00 2001
From: "kfraser@localhost.localdomain" <kfraser@localhost.localdomain>
Date: Thu, 7 Dec 2006 11:52:26 +0000
Subject: [PATCH] [HVM] qemu mouse: Adds support for USB mouse/tablet status
 check and restricts Universal Host Controller interrupt generating when
 received NAK in interrupt transfer.

According to usb spec, USB mouse/tablet device returns NAK to host
controller if its status does not alter in interrupt transfer.
And UHC should leave a TD active when receiving NAK and execute this
incompleted TD in a subseqent frame. UHC only generates an interrupt
on complete after the TD with ICO bit is completed.

This patch make UHC & USB mouse/tablet behave consistently with spec.

Signed-off-by: Xinmei Huang <xinmei.huang@intel.com>
---
 tools/ioemu/hw/usb-hid.c  | 19 +++++++++++++++----
 tools/ioemu/hw/usb-uhci.c | 36 ++++++++++++++++++++++++------------
 2 files changed, 39 insertions(+), 16 deletions(-)

diff --git a/tools/ioemu/hw/usb-hid.c b/tools/ioemu/hw/usb-hid.c
index 8fc0b744b7..60849a4ed0 100644
--- a/tools/ioemu/hw/usb-hid.c
+++ b/tools/ioemu/hw/usb-hid.c
@@ -39,6 +39,7 @@ typedef struct USBMouseState {
     int x, y;
     int kind;
     int mouse_grabbed;
+    int status_changed;
 } USBMouseState;
 
 /* mostly the same values as the Bochs USB Mouse device */
@@ -231,6 +232,7 @@ static void usb_mouse_event(void *opaque,
     s->dy += dy1;
     s->dz += dz1;
     s->buttons_state = buttons_state;
+    s->status_changed = 1;
 }
 
 static void usb_tablet_event(void *opaque,
@@ -242,6 +244,7 @@ static void usb_tablet_event(void *opaque,
     s->y = y;
     s->dz += dz;
     s->buttons_state = buttons_state;
+    s->status_changed = 1;
 }
 
 static inline int int_clamp(int val, int vmin, int vmax)
@@ -483,10 +486,16 @@ static int usb_mouse_handle_data(USBDevice *dev, int pid,
     switch(pid) {
     case USB_TOKEN_IN:
         if (devep == 1) {
-	    if (s->kind == USB_MOUSE)
-		ret = usb_mouse_poll(s, data, len);
-	    else if (s->kind == USB_TABLET)
-		ret = usb_tablet_poll(s, data, len);
+            if (s->kind == USB_MOUSE)
+                ret = usb_mouse_poll(s, data, len);
+            else if (s->kind == USB_TABLET)
+                ret = usb_tablet_poll(s, data, len);
+
+            if (!s->status_changed)
+                ret = USB_RET_NAK;
+            else
+                s->status_changed = 0;
+
         } else {
             goto fail;
         }
@@ -523,6 +532,7 @@ USBDevice *usb_tablet_init(void)
     s->dev.handle_data = usb_mouse_handle_data;
     s->dev.handle_destroy = usb_mouse_handle_destroy;
     s->kind = USB_TABLET;
+    s->status_changed = 0;
 
     pstrcpy(s->dev.devname, sizeof(s->dev.devname), "QEMU USB Tablet");
 
@@ -544,6 +554,7 @@ USBDevice *usb_mouse_init(void)
     s->dev.handle_data = usb_mouse_handle_data;
     s->dev.handle_destroy = usb_mouse_handle_destroy;
     s->kind = USB_MOUSE;
+    s->status_changed = 0;
 
     pstrcpy(s->dev.devname, sizeof(s->dev.devname), "QEMU USB Mouse");
 
diff --git a/tools/ioemu/hw/usb-uhci.c b/tools/ioemu/hw/usb-uhci.c
index 4b8db28717..9503c51c3e 100644
--- a/tools/ioemu/hw/usb-uhci.c
+++ b/tools/ioemu/hw/usb-uhci.c
@@ -424,12 +424,10 @@ static int uhci_handle_td(UHCIState *s, UHCI_TD *td, int *int_mask)
     uint8_t buf[2048];
     int len, max_len, err, ret;
 
-    if (td->ctrl & TD_CTRL_IOC) {
-        *int_mask |= 0x01;
+    if (!(td->ctrl & TD_CTRL_ACTIVE)){
+        ret = 1;
+        goto out;
     }
-    
-    if (!(td->ctrl & TD_CTRL_ACTIVE))
-        return 1;
 
     /* TD is active */
     max_len = ((td->token >> 21) + 1) & 0x7ff;
@@ -467,7 +465,8 @@ static int uhci_handle_td(UHCIState *s, UHCI_TD *td, int *int_mask)
         /* invalid pid : frame interrupted */
         s->status |= UHCI_STS_HCPERR;
         uhci_update_irq(s);
-        return -1;
+        ret = -1;
+        goto out;
     }
     if (td->ctrl & TD_CTRL_IOS)
         td->ctrl &= ~TD_CTRL_ACTIVE;
@@ -479,10 +478,12 @@ static int uhci_handle_td(UHCIState *s, UHCI_TD *td, int *int_mask)
             len < max_len) {
             *int_mask |= 0x02;
             /* short packet: do not update QH */
-            return 1;
+            ret = 1;
+            goto out;
         } else {
             /* success */
-            return 0;
+            ret = 0;
+            goto out;
         }
     } else {
         switch(ret) {
@@ -501,23 +502,34 @@ static int uhci_handle_td(UHCIState *s, UHCI_TD *td, int *int_mask)
             }
             td->ctrl = (td->ctrl & ~(3 << TD_CTRL_ERROR_SHIFT)) | 
                 (err << TD_CTRL_ERROR_SHIFT);
-            return 1;
+            ret = 1;
+            goto out;
         case USB_RET_NAK:
             td->ctrl |= TD_CTRL_NAK;
             if (pid == USB_TOKEN_SETUP)
                 goto do_timeout;
-            return 1;
+            ret = 1;
+            goto out;
         case USB_RET_STALL:
             td->ctrl |= TD_CTRL_STALL;
             td->ctrl &= ~TD_CTRL_ACTIVE;
-            return 1;
+            ret = 1;
+            goto out;
         case USB_RET_BABBLE:
             td->ctrl |= TD_CTRL_BABBLE | TD_CTRL_STALL;
             td->ctrl &= ~TD_CTRL_ACTIVE;
             /* frame interrupted */
-            return -1;
+            ret = -1;
+            goto out;
         }
     }
+   
+out:
+    /* If TD is inactive and IOC bit set to 1 then update int_mask */ 
+    if ((td->ctrl & TD_CTRL_IOC) && (!(td->ctrl & TD_CTRL_ACTIVE))) {
+        *int_mask |= 0x01;
+    }
+    return ret;
 }
 
 static void uhci_frame_timer(void *opaque)
-- 
2.30.2