[Qemu-devel] [PATCH 3/3] usb-mtp: add support for basic mtp events

[Bandan Das <bsd@redhat.com>]

When the host polls for events, we check our
events qlist and send one event at a time. Also, note
that the event packet needs to be sent in one go, so
I increased the max packet size to 64.

Tested with a linux guest.

Signed-off-by: Bandan Das <bsd@redhat.com>
---
 hw/usb/dev-mtp.c | 44 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 79d4ab0..ad33ee8 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -64,6 +64,11 @@ enum mtp_code {
     /* format codes */
     FMT_UNDEFINED_OBJECT           = 0x3000,
     FMT_ASSOCIATION                = 0x3001,
+
+    /* event codes */
+    EVT_OBJ_ADDED                  = 0x4002,
+    EVT_OBJ_REMOVED                = 0x4003,
+    EVT_OBJ_INFO_CHANGED           = 0x4007,
 };
 
 typedef struct {
@@ -94,12 +99,6 @@ struct MTPMonEntry {
     QTAILQ_ENTRY(MTPMonEntry) next;
 };
 
-enum inotify_event_type {
-    CREATE = 1,
-    DELETE = 2,
-    MODIFY = 3,
-};
-
 struct MTPControl {
     uint16_t     code;
     uint32_t     trans;
@@ -205,7 +204,7 @@ static const USBDescIface desc_iface_full = {
         },{
             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
             .bmAttributes          = USB_ENDPOINT_XFER_INT,
-            .wMaxPacketSize        = 8,
+            .wMaxPacketSize        = 64,
             .bInterval             = 0x0a,
         },
     }
@@ -247,7 +246,7 @@ static const USBDescIface desc_iface_high = {
         },{
             .bEndpointAddress      = USB_DIR_IN | EP_EVENT,
             .bmAttributes          = USB_ENDPOINT_XFER_INT,
-            .wMaxPacketSize        = 8,
+            .wMaxPacketSize        = 64,
             .bInterval             = 0x0a,
         },
     }
@@ -526,7 +525,7 @@ static void inotify_watchfn(void *arg)
 
                 entry = g_new0(MTPMonEntry, 1);
                 entry->handle = s->next_handle;
-                entry->event = CREATE;
+                entry->event = EVT_OBJ_ADDED;
                 o = usb_mtp_add_child(s, parent, event->name);
                 if (!o) {
                     error = 1;
@@ -551,7 +550,7 @@ static void inotify_watchfn(void *arg)
                 }
                 entry = g_new0(MTPMonEntry, 1);
                 entry->handle = o->handle;
-                entry->event = DELETE;
+                entry->event = EVT_OBJ_REMOVED;
                 usb_mtp_object_free(s, o);
                 trace_usb_mtp_inotify_event(s->dev.addr, o->path,
                                       event->mask, "Obj Deleted");
@@ -565,7 +564,7 @@ static void inotify_watchfn(void *arg)
                 }
                 entry = g_new0(MTPMonEntry, 1);
                 entry->handle = o->handle;
-                entry->event = MODIFY;
+                entry->event = EVT_OBJ_INFO_CHANGED;
                 trace_usb_mtp_inotify_event(s->dev.addr, o->path,
                                       event->mask, "Obj Modified");
                 break;
@@ -1313,6 +1312,29 @@ static void usb_mtp_handle_data(USBDevice *dev, USBPacket *p)
         }
         break;
     case EP_EVENT:
+        if (!QTAILQ_EMPTY(&s->events)) {
+            struct MTPMonEntry *e = QTAILQ_LAST(&s->events, events);
+            uint32_t handle;
+            int len = sizeof(container) + sizeof(uint32_t);
+
+            if (p->iov.size < len) {
+                trace_usb_mtp_stall(s->dev.addr,
+                                    "packet too small to send event");
+                p->status = USB_RET_STALL;
+                return;
+            }
+
+            QTAILQ_REMOVE(&s->events, e, next);
+            container.length = cpu_to_le32(len);
+            container.type = cpu_to_le32(TYPE_EVENT);
+            container.code = cpu_to_le16(e->event);
+            container.trans = 0; /* no trans specific events */
+            handle = cpu_to_le32(e->handle);
+            usb_packet_copy(p, &container, sizeof(container));
+            usb_packet_copy(p, &handle, sizeof(uint32_t));
+            g_free(e);
+            return;
+        }
         p->status = USB_RET_NAK;
         return;
     default:
-- 
2.4.3