--- qemu/usb-linux.c	2018/04/24 18:56:03	1.1.1.13
+++ qemu/usb-linux.c	2018/04/24 19:17:08	1.1.1.14
@@ -34,6 +34,7 @@
 #include "qemu-timer.h"
 #include "monitor.h"
 #include "sysemu.h"
+#include "trace.h"
 
 #include <dirent.h>
 #include <sys/ioctl.h>
@@ -53,7 +54,7 @@ struct usb_ctrltransfer {
     void *data;
 };
 
-typedef int USBScanFunc(void *opaque, int bus_num, int addr, char *port,
+typedef int USBScanFunc(void *opaque, int bus_num, int addr, const char *port,
                         int class_id, int vendor_id, int product_id,
                         const char *product_name, int speed);
 
@@ -114,6 +115,8 @@ struct USBAutoFilter {
 typedef struct USBHostDevice {
     USBDevice dev;
     int       fd;
+    int       hub_fd;
+    int       hub_port;
 
     uint8_t   descr[8192];
     int       descr_len;
@@ -123,7 +126,8 @@ typedef struct USBHostDevice {
     uint32_t  iso_urb_count;
     Notifier  exit;
 
-    struct endp_data endp_table[MAX_ENDPOINTS];
+    struct endp_data ep_in[MAX_ENDPOINTS];
+    struct endp_data ep_out[MAX_ENDPOINTS];
     QLIST_HEAD(, AsyncURB) aurbs;
 
     /* Host side address */
@@ -131,6 +135,7 @@ typedef struct USBHostDevice {
     int addr;
     char port[MAX_PORTLEN];
     struct USBAutoFilter match;
+    int seen, errcount;
 
     QTAILQ_ENTRY(USBHostDevice) next;
 } USBHostDevice;
@@ -142,95 +147,126 @@ static int parse_filter(const char *spec
 static void usb_host_auto_check(void *unused);
 static int usb_host_read_file(char *line, size_t line_size,
                             const char *device_file, const char *device_name);
+static int usb_linux_update_endp_table(USBHostDevice *s);
+
+static int usb_host_do_reset(USBHostDevice *dev)
+{
+    struct timeval s, e;
+    uint32_t usecs;
+    int ret;
+
+    gettimeofday(&s, NULL);
+    ret = ioctl(dev->fd, USBDEVFS_RESET);
+    gettimeofday(&e, NULL);
+    usecs = (e.tv_sec  - s.tv_sec) * 1000000;
+    usecs += e.tv_usec - s.tv_usec;
+    if (usecs > 1000000) {
+        /* more than a second, something is fishy, broken usb device? */
+        fprintf(stderr, "husb: device %d:%d reset took %d.%06d seconds\n",
+                dev->bus_num, dev->addr, usecs / 1000000, usecs % 1000000);
+    }
+    return ret;
+}
 
-static struct endp_data *get_endp(USBHostDevice *s, int ep)
+static struct endp_data *get_endp(USBHostDevice *s, int pid, int ep)
 {
-    return s->endp_table + ep - 1;
+    struct endp_data *eps = pid == USB_TOKEN_IN ? s->ep_in : s->ep_out;
+    assert(pid == USB_TOKEN_IN || pid == USB_TOKEN_OUT);
+    assert(ep > 0 && ep <= MAX_ENDPOINTS);
+    return eps + ep - 1;
 }
 
-static int is_isoc(USBHostDevice *s, int ep)
+static int is_isoc(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->type == USBDEVFS_URB_TYPE_ISO;
+    return get_endp(s, pid, ep)->type == USBDEVFS_URB_TYPE_ISO;
 }
 
-static int is_valid(USBHostDevice *s, int ep)
+static int is_valid(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->type != INVALID_EP_TYPE;
+    return get_endp(s, pid, ep)->type != INVALID_EP_TYPE;
 }
 
-static int is_halted(USBHostDevice *s, int ep)
+static int is_halted(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->halted;
+    return get_endp(s, pid, ep)->halted;
 }
 
-static void clear_halt(USBHostDevice *s, int ep)
+static void clear_halt(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->halted = 0;
+    trace_usb_host_ep_clear_halt(s->bus_num, s->addr, ep);
+    get_endp(s, pid, ep)->halted = 0;
 }
 
-static void set_halt(USBHostDevice *s, int ep)
+static void set_halt(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->halted = 1;
+    if (ep != 0) {
+        trace_usb_host_ep_set_halt(s->bus_num, s->addr, ep);
+        get_endp(s, pid, ep)->halted = 1;
+    }
 }
 
-static int is_iso_started(USBHostDevice *s, int ep)
+static int is_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_started;
+    return get_endp(s, pid, ep)->iso_started;
 }
 
-static void clear_iso_started(USBHostDevice *s, int ep)
+static void clear_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->iso_started = 0;
+    trace_usb_host_ep_stop_iso(s->bus_num, s->addr, ep);
+    get_endp(s, pid, ep)->iso_started = 0;
 }
 
-static void set_iso_started(USBHostDevice *s, int ep)
+static void set_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    struct endp_data *e = get_endp(s, ep);
+    struct endp_data *e = get_endp(s, pid, ep);
+
+    trace_usb_host_ep_start_iso(s->bus_num, s->addr, ep);
     if (!e->iso_started) {
         e->iso_started = 1;
         e->inflight = 0;
     }
 }
 
-static int change_iso_inflight(USBHostDevice *s, int ep, int value)
+static int change_iso_inflight(USBHostDevice *s, int pid, int ep, int value)
 {
-    struct endp_data *e = get_endp(s, ep);
+    struct endp_data *e = get_endp(s, pid, ep);
 
     e->inflight += value;
     return e->inflight;
 }
 
-static void set_iso_urb(USBHostDevice *s, int ep, AsyncURB *iso_urb)
+static void set_iso_urb(USBHostDevice *s, int pid, int ep, AsyncURB *iso_urb)
 {
-    get_endp(s, ep)->iso_urb = iso_urb;
+    get_endp(s, pid, ep)->iso_urb = iso_urb;
 }
 
-static AsyncURB *get_iso_urb(USBHostDevice *s, int ep)
+static AsyncURB *get_iso_urb(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_urb;
+    return get_endp(s, pid, ep)->iso_urb;
 }
 
-static void set_iso_urb_idx(USBHostDevice *s, int ep, int i)
+static void set_iso_urb_idx(USBHostDevice *s, int pid, int ep, int i)
 {
-    get_endp(s, ep)->iso_urb_idx = i;
+    get_endp(s, pid, ep)->iso_urb_idx = i;
 }
 
-static int get_iso_urb_idx(USBHostDevice *s, int ep)
+static int get_iso_urb_idx(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_urb_idx;
+    return get_endp(s, pid, ep)->iso_urb_idx;
 }
 
-static void set_iso_buffer_used(USBHostDevice *s, int ep, int i)
+static void set_iso_buffer_used(USBHostDevice *s, int pid, int ep, int i)
 {
-    get_endp(s, ep)->iso_buffer_used = i;
+    get_endp(s, pid, ep)->iso_buffer_used = i;
 }
 
-static int get_iso_buffer_used(USBHostDevice *s, int ep)
+static int get_iso_buffer_used(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_buffer_used;
+    return get_endp(s, pid, ep)->iso_buffer_used;
 }
 
-static void set_max_packet_size(USBHostDevice *s, int ep, uint8_t *descriptor)
+static void set_max_packet_size(USBHostDevice *s, int pid, int ep,
+                                uint8_t *descriptor)
 {
     int raw = descriptor[4] + (descriptor[5] << 8);
     int size, microframes;
@@ -241,12 +277,12 @@ static void set_max_packet_size(USBHostD
     case 2:  microframes = 3; break;
     default: microframes = 1; break;
     }
-    get_endp(s, ep)->max_packet_size = size * microframes;
+    get_endp(s, pid, ep)->max_packet_size = size * microframes;
 }
 
-static int get_max_packet_size(USBHostDevice *s, int ep)
+static int get_max_packet_size(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->max_packet_size;
+    return get_endp(s, pid, ep)->max_packet_size;
 }
 
 /*
@@ -271,7 +307,7 @@ struct AsyncURB
 
 static AsyncURB *async_alloc(USBHostDevice *s)
 {
-    AsyncURB *aurb = qemu_mallocz(sizeof(AsyncURB));
+    AsyncURB *aurb = g_malloc0(sizeof(AsyncURB));
     aurb->hdev = s;
     QLIST_INSERT_HEAD(&s->aurbs, aurb, next);
     return aurb;
@@ -280,13 +316,11 @@ static AsyncURB *async_alloc(USBHostDevi
 static void async_free(AsyncURB *aurb)
 {
     QLIST_REMOVE(aurb, next);
-    qemu_free(aurb);
+    g_free(aurb);
 }
 
 static void do_disconnect(USBHostDevice *s)
 {
-    printf("husb: device %d.%d disconnected\n",
-           s->bus_num, s->addr);
     usb_host_close(s);
     usb_host_auto_check(NULL);
 }
@@ -308,12 +342,15 @@ static void async_complete(void *opaque)
                 }
                 return;
             }
-            if (errno == ENODEV && !s->closing) {
-                do_disconnect(s);
+            if (errno == ENODEV) {
+                if (!s->closing) {
+                    trace_usb_host_disconnect(s->bus_num, s->addr);
+                    do_disconnect(s);
+                }
                 return;
             }
 
-            DPRINTF("husb: async. reap urb failed errno %d\n", errno);
+            perror("USBDEVFS_REAPURBNDELAY");
             return;
         }
 
@@ -324,39 +361,46 @@ static void async_complete(void *opaque)
            anything else (it is handled further in usb_host_handle_iso_data) */
         if (aurb->iso_frame_idx == -1) {
             int inflight;
+            int pid = (aurb->urb.endpoint & USB_DIR_IN) ?
+                USB_TOKEN_IN : USB_TOKEN_OUT;
+            int ep = aurb->urb.endpoint & 0xf;
             if (aurb->urb.status == -EPIPE) {
-                set_halt(s, aurb->urb.endpoint & 0xf);
+                set_halt(s, pid, ep);
             }
             aurb->iso_frame_idx = 0;
             urbs++;
-            inflight = change_iso_inflight(s, aurb->urb.endpoint & 0xf, -1);
-            if (inflight == 0 && is_iso_started(s, aurb->urb.endpoint & 0xf)) {
+            inflight = change_iso_inflight(s, pid, ep, -1);
+            if (inflight == 0 && is_iso_started(s, pid, ep)) {
                 fprintf(stderr, "husb: out of buffers for iso stream\n");
             }
             continue;
         }
 
         p = aurb->packet;
+        trace_usb_host_urb_complete(s->bus_num, s->addr, aurb, aurb->urb.status,
+                                    aurb->urb.actual_length, aurb->more);
 
         if (p) {
             switch (aurb->urb.status) {
             case 0:
-                p->len += aurb->urb.actual_length;
+                p->result += aurb->urb.actual_length;
                 break;
 
             case -EPIPE:
-                set_halt(s, p->devep);
-                p->len = USB_RET_STALL;
+                set_halt(s, p->pid, p->devep);
+                p->result = USB_RET_STALL;
                 break;
 
             default:
-                p->len = USB_RET_NAK;
+                p->result = USB_RET_NAK;
                 break;
             }
 
             if (aurb->urb.type == USBDEVFS_URB_TYPE_CONTROL) {
+                trace_usb_host_req_complete(s->bus_num, s->addr, p->result);
                 usb_generic_async_ctrl_complete(&s->dev, p);
             } else if (!aurb->more) {
+                trace_usb_host_req_complete(s->bus_num, s->addr, p->result);
                 usb_packet_complete(&s->dev, p);
             }
         }
@@ -387,6 +431,112 @@ static void usb_host_async_cancel(USBDev
     }
 }
 
+static int usb_host_claim_port(USBHostDevice *s)
+{
+#ifdef USBDEVFS_CLAIM_PORT
+    char *h, hub_name[64], line[1024];
+    int hub_addr, ret;
+
+    snprintf(hub_name, sizeof(hub_name), "%d-%s",
+             s->match.bus_num, s->match.port);
+
+    /* try strip off last ".$portnr" to get hub */
+    h = strrchr(hub_name, '.');
+    if (h != NULL) {
+        s->hub_port = atoi(h+1);
+        *h = '\0';
+    } else {
+        /* no dot in there -> it is the root hub */
+        snprintf(hub_name, sizeof(hub_name), "usb%d",
+                 s->match.bus_num);
+        s->hub_port = atoi(s->match.port);
+    }
+
+    if (!usb_host_read_file(line, sizeof(line), "devnum",
+                            hub_name)) {
+        return -1;
+    }
+    if (sscanf(line, "%d", &hub_addr) != 1) {
+        return -1;
+    }
+
+    if (!usb_host_device_path) {
+        return -1;
+    }
+    snprintf(line, sizeof(line), "%s/%03d/%03d",
+             usb_host_device_path, s->match.bus_num, hub_addr);
+    s->hub_fd = open(line, O_RDWR | O_NONBLOCK);
+    if (s->hub_fd < 0) {
+        return -1;
+    }
+
+    ret = ioctl(s->hub_fd, USBDEVFS_CLAIM_PORT, &s->hub_port);
+    if (ret < 0) {
+        close(s->hub_fd);
+        s->hub_fd = -1;
+        return -1;
+    }
+
+    trace_usb_host_claim_port(s->match.bus_num, hub_addr, s->hub_port);
+    return 0;
+#else
+    return -1;
+#endif
+}
+
+static void usb_host_release_port(USBHostDevice *s)
+{
+    if (s->hub_fd == -1) {
+        return;
+    }
+#ifdef USBDEVFS_RELEASE_PORT
+    ioctl(s->hub_fd, USBDEVFS_RELEASE_PORT, &s->hub_port);
+#endif
+    close(s->hub_fd);
+    s->hub_fd = -1;
+}
+
+static int usb_host_disconnect_ifaces(USBHostDevice *dev, int nb_interfaces)
+{
+    /* earlier Linux 2.4 do not support that */
+#ifdef USBDEVFS_DISCONNECT
+    struct usbdevfs_ioctl ctrl;
+    int ret, interface;
+
+    for (interface = 0; interface < nb_interfaces; interface++) {
+        ctrl.ioctl_code = USBDEVFS_DISCONNECT;
+        ctrl.ifno = interface;
+        ctrl.data = 0;
+        ret = ioctl(dev->fd, USBDEVFS_IOCTL, &ctrl);
+        if (ret < 0 && errno != ENODATA) {
+            perror("USBDEVFS_DISCONNECT");
+            return -1;
+        }
+    }
+#endif
+    return 0;
+}
+
+static int usb_linux_get_num_interfaces(USBHostDevice *s)
+{
+    char device_name[64], line[1024];
+    int num_interfaces = 0;
+
+    if (usb_fs_type != USB_FS_SYS) {
+        return -1;
+    }
+
+    sprintf(device_name, "%d-%s", s->bus_num, s->port);
+    if (!usb_host_read_file(line, sizeof(line), "bNumInterfaces",
+                            device_name)) {
+        return -1;
+    }
+    if (sscanf(line, "%d", &num_interfaces) != 1) {
+        return -1;
+    }
+    return num_interfaces;
+}
+
 static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
 {
     const char *op = NULL;
@@ -394,8 +544,11 @@ static int usb_host_claim_interfaces(USB
     int interface, nb_interfaces;
     int ret, i;
 
-    if (configuration == 0) /* address state - ignore */
+    if (configuration == 0) { /* address state - ignore */
+        dev->ninterfaces   = 0;
+        dev->configuration = 0;
         return 1;
+    }
 
     DPRINTF("husb: claiming interfaces. config %d\n", configuration);
 
@@ -418,9 +571,9 @@ static int usb_host_claim_interfaces(USB
         }
         config_descr_len = dev->descr[i];
 
-        printf("husb: config #%d need %d\n", dev->descr[i + 5], configuration);
+        DPRINTF("husb: config #%d need %d\n", dev->descr[i + 5], configuration);
 
-        if (configuration < 0 || configuration == dev->descr[i + 5]) {
+        if (configuration == dev->descr[i + 5]) {
             configuration = dev->descr[i + 5];
             break;
         }
@@ -435,39 +588,21 @@ static int usb_host_claim_interfaces(USB
     }
     nb_interfaces = dev->descr[i + 4];
 
-#ifdef USBDEVFS_DISCONNECT
-    /* earlier Linux 2.4 do not support that */
-    {
-        struct usbdevfs_ioctl ctrl;
-        for (interface = 0; interface < nb_interfaces; interface++) {
-            ctrl.ioctl_code = USBDEVFS_DISCONNECT;
-            ctrl.ifno = interface;
-            ctrl.data = 0;
-            op = "USBDEVFS_DISCONNECT";
-            ret = ioctl(dev->fd, USBDEVFS_IOCTL, &ctrl);
-            if (ret < 0 && errno != ENODATA) {
-                goto fail;
-            }
-        }
+    if (usb_host_disconnect_ifaces(dev, nb_interfaces) < 0) {
+        goto fail;
     }
-#endif
 
     /* XXX: only grab if all interfaces are free */
     for (interface = 0; interface < nb_interfaces; interface++) {
         op = "USBDEVFS_CLAIMINTERFACE";
         ret = ioctl(dev->fd, USBDEVFS_CLAIMINTERFACE, &interface);
         if (ret < 0) {
-            if (errno == EBUSY) {
-                printf("husb: update iface. device already grabbed\n");
-            } else {
-                perror("husb: failed to claim interface");
-            }
             goto fail;
         }
     }
 
-    printf("husb: %d interfaces claimed for configuration %d\n",
-           nb_interfaces, configuration);
+    trace_usb_host_claim_interfaces(dev->bus_num, dev->addr,
+                                    nb_interfaces, configuration);
 
     dev->ninterfaces   = nb_interfaces;
     dev->configuration = configuration;
@@ -485,16 +620,15 @@ static int usb_host_release_interfaces(U
 {
     int ret, i;
 
-    DPRINTF("husb: releasing interfaces\n");
+    trace_usb_host_release_interfaces(s->bus_num, s->addr);
 
     for (i = 0; i < s->ninterfaces; i++) {
         ret = ioctl(s->fd, USBDEVFS_RELEASEINTERFACE, &i);
         if (ret < 0) {
-            perror("husb: failed to release interface");
+            perror("USBDEVFS_RELEASEINTERFACE");
             return 0;
         }
     }
-
     return 1;
 }
 
@@ -502,59 +636,59 @@ static void usb_host_handle_reset(USBDev
 {
     USBHostDevice *s = DO_UPCAST(USBHostDevice, dev, dev);
 
-    DPRINTF("husb: reset device %u.%u\n", s->bus_num, s->addr);
+    trace_usb_host_reset(s->bus_num, s->addr);
 
-    ioctl(s->fd, USBDEVFS_RESET);
+    usb_host_do_reset(s);;
 
-    usb_host_claim_interfaces(s, s->configuration);
+    usb_host_claim_interfaces(s, 0);
+    usb_linux_update_endp_table(s);
 }
 
 static void usb_host_handle_destroy(USBDevice *dev)
 {
     USBHostDevice *s = (USBHostDevice *)dev;
 
+    usb_host_release_port(s);
     usb_host_close(s);
     QTAILQ_REMOVE(&hostdevs, s, next);
     qemu_remove_exit_notifier(&s->exit);
 }
 
-static int usb_linux_update_endp_table(USBHostDevice *s);
-
 /* iso data is special, we need to keep enough urbs in flight to make sure
    that the controller never runs out of them, otherwise the device will
    likely suffer a buffer underrun / overrun. */
-static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, uint8_t ep, int in)
+static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, int pid, uint8_t ep)
 {
     AsyncURB *aurb;
-    int i, j, len = get_max_packet_size(s, ep);
+    int i, j, len = get_max_packet_size(s, pid, ep);
 
-    aurb = qemu_mallocz(s->iso_urb_count * sizeof(*aurb));
+    aurb = g_malloc0(s->iso_urb_count * sizeof(*aurb));
     for (i = 0; i < s->iso_urb_count; i++) {
         aurb[i].urb.endpoint      = ep;
         aurb[i].urb.buffer_length = ISO_FRAME_DESC_PER_URB * len;
-        aurb[i].urb.buffer        = qemu_malloc(aurb[i].urb.buffer_length);
+        aurb[i].urb.buffer        = g_malloc(aurb[i].urb.buffer_length);
         aurb[i].urb.type          = USBDEVFS_URB_TYPE_ISO;
         aurb[i].urb.flags         = USBDEVFS_URB_ISO_ASAP;
         aurb[i].urb.number_of_packets = ISO_FRAME_DESC_PER_URB;
         for (j = 0 ; j < ISO_FRAME_DESC_PER_URB; j++)
             aurb[i].urb.iso_frame_desc[j].length = len;
-        if (in) {
+        if (pid == USB_TOKEN_IN) {
             aurb[i].urb.endpoint |= 0x80;
             /* Mark as fully consumed (idle) */
             aurb[i].iso_frame_idx = ISO_FRAME_DESC_PER_URB;
         }
     }
-    set_iso_urb(s, ep, aurb);
+    set_iso_urb(s, pid, ep, aurb);
 
     return aurb;
 }
 
-static void usb_host_stop_n_free_iso(USBHostDevice *s, uint8_t ep)
+static void usb_host_stop_n_free_iso(USBHostDevice *s, int pid, uint8_t ep)
 {
     AsyncURB *aurb;
     int i, ret, killed = 0, free = 1;
 
-    aurb = get_iso_urb(s, ep);
+    aurb = get_iso_urb(s, pid, ep);
     if (!aurb) {
         return;
     }
@@ -564,7 +698,7 @@ static void usb_host_stop_n_free_iso(USB
         if (aurb[i].iso_frame_idx == -1) {
             ret = ioctl(s->fd, USBDEVFS_DISCARDURB, &aurb[i]);
             if (ret < 0) {
-                printf("husb: discard isoc in urb failed errno %d\n", errno);
+                perror("USBDEVFS_DISCARDURB");
                 free = 0;
                 continue;
             }
@@ -578,16 +712,16 @@ static void usb_host_stop_n_free_iso(USB
     }
 
     for (i = 0; i < s->iso_urb_count; i++) {
-        qemu_free(aurb[i].urb.buffer);
+        g_free(aurb[i].urb.buffer);
     }
 
     if (free)
-        qemu_free(aurb);
+        g_free(aurb);
     else
         printf("husb: leaking iso urbs because of discard failure\n");
-    set_iso_urb(s, ep, NULL);
-    set_iso_urb_idx(s, ep, 0);
-    clear_iso_started(s, ep);
+    set_iso_urb(s, pid, ep, NULL);
+    set_iso_urb_idx(s, pid, ep, 0);
+    clear_iso_started(s, pid, ep);
 }
 
 static int urb_status_to_usb_ret(int status)
@@ -604,17 +738,18 @@ static int usb_host_handle_iso_data(USBH
 {
     AsyncURB *aurb;
     int i, j, ret, max_packet_size, offset, len = 0;
+    uint8_t *buf;
 
-    max_packet_size = get_max_packet_size(s, p->devep);
+    max_packet_size = get_max_packet_size(s, p->pid, p->devep);
     if (max_packet_size == 0)
         return USB_RET_NAK;
 
-    aurb = get_iso_urb(s, p->devep);
+    aurb = get_iso_urb(s, p->pid, p->devep);
     if (!aurb) {
-        aurb = usb_host_alloc_iso(s, p->devep, in);
+        aurb = usb_host_alloc_iso(s, p->pid, p->devep);
     }
 
-    i = get_iso_urb_idx(s, p->devep);
+    i = get_iso_urb_idx(s, p->pid, p->devep);
     j = aurb[i].iso_frame_idx;
     if (j >= 0 && j < ISO_FRAME_DESC_PER_URB) {
         if (in) {
@@ -628,20 +763,20 @@ static int usb_host_handle_iso_data(USBH
                 len = urb_status_to_usb_ret(
                                         aurb[i].urb.iso_frame_desc[j].status);
             /* Check the frame fits */
-            } else if (aurb[i].urb.iso_frame_desc[j].actual_length > p->len) {
+            } else if (aurb[i].urb.iso_frame_desc[j].actual_length
+                       > p->iov.size) {
                 printf("husb: received iso data is larger then packet\n");
                 len = USB_RET_NAK;
             /* All good copy data over */
             } else {
                 len = aurb[i].urb.iso_frame_desc[j].actual_length;
-                memcpy(p->data,
-                       aurb[i].urb.buffer +
-                           j * aurb[i].urb.iso_frame_desc[0].length,
-                       len);
+                buf  = aurb[i].urb.buffer +
+                    j * aurb[i].urb.iso_frame_desc[0].length;
+                usb_packet_copy(p, buf, len);
             }
         } else {
-            len = p->len;
-            offset = (j == 0) ? 0 : get_iso_buffer_used(s, p->devep);
+            len = p->iov.size;
+            offset = (j == 0) ? 0 : get_iso_buffer_used(s, p->pid, p->devep);
 
             /* Check the frame fits */
             if (len > max_packet_size) {
@@ -650,36 +785,36 @@ static int usb_host_handle_iso_data(USBH
             }
 
             /* All good copy data over */
-            memcpy(aurb[i].urb.buffer + offset, p->data, len);
+            usb_packet_copy(p, aurb[i].urb.buffer + offset, len);
             aurb[i].urb.iso_frame_desc[j].length = len;
             offset += len;
-            set_iso_buffer_used(s, p->devep, offset);
+            set_iso_buffer_used(s, p->pid, p->devep, offset);
 
             /* Start the stream once we have buffered enough data */
-            if (!is_iso_started(s, p->devep) && i == 1 && j == 8) {
-                set_iso_started(s, p->devep);
+            if (!is_iso_started(s, p->pid, p->devep) && i == 1 && j == 8) {
+                set_iso_started(s, p->pid, p->devep);
             }
         }
         aurb[i].iso_frame_idx++;
         if (aurb[i].iso_frame_idx == ISO_FRAME_DESC_PER_URB) {
             i = (i + 1) % s->iso_urb_count;
-            set_iso_urb_idx(s, p->devep, i);
+            set_iso_urb_idx(s, p->pid, p->devep, i);
         }
     } else {
         if (in) {
-            set_iso_started(s, p->devep);
+            set_iso_started(s, p->pid, p->devep);
         } else {
             DPRINTF("hubs: iso out error no free buffer, dropping packet\n");
         }
     }
 
-    if (is_iso_started(s, p->devep)) {
+    if (is_iso_started(s, p->pid, p->devep)) {
         /* (Re)-submit all fully consumed / filled urbs */
         for (i = 0; i < s->iso_urb_count; i++) {
             if (aurb[i].iso_frame_idx == ISO_FRAME_DESC_PER_URB) {
                 ret = ioctl(s->fd, USBDEVFS_SUBMITURB, &aurb[i]);
                 if (ret < 0) {
-                    printf("husb error submitting iso urb %d: %d\n", i, errno);
+                    perror("USBDEVFS_SUBMITURB");
                     if (!in || len == 0) {
                         switch(errno) {
                         case ETIMEDOUT:
@@ -693,7 +828,7 @@ static int usb_host_handle_iso_data(USBH
                     break;
                 }
                 aurb[i].iso_frame_idx = -1;
-                change_iso_inflight(s, p->devep, +1);
+                change_iso_inflight(s, p->pid, p->devep, 1);
             }
         }
     }
@@ -706,11 +841,16 @@ static int usb_host_handle_data(USBDevic
     USBHostDevice *s = DO_UPCAST(USBHostDevice, dev, dev);
     struct usbdevfs_urb *urb;
     AsyncURB *aurb;
-    int ret, rem;
+    int ret, rem, prem, v;
     uint8_t *pbuf;
     uint8_t ep;
 
-    if (!is_valid(s, p->devep)) {
+    trace_usb_host_req_data(s->bus_num, s->addr,
+                            p->pid == USB_TOKEN_IN,
+                            p->devep, p->iov.size);
+
+    if (!is_valid(s, p->pid, p->devep)) {
+        trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
         return USB_RET_NAK;
     }
 
@@ -720,24 +860,33 @@ static int usb_host_handle_data(USBDevic
         ep = p->devep;
     }
 
-    if (is_halted(s, p->devep)) {
-        ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &ep);
+    if (is_halted(s, p->pid, p->devep)) {
+        unsigned int arg = ep;
+        ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &arg);
         if (ret < 0) {
-            DPRINTF("husb: failed to clear halt. ep 0x%x errno %d\n",
-                   ep, errno);
+            perror("USBDEVFS_CLEAR_HALT");
+            trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
             return USB_RET_NAK;
         }
-        clear_halt(s, p->devep);
+        clear_halt(s, p->pid, p->devep);
     }
 
-    if (is_isoc(s, p->devep)) {
+    if (is_isoc(s, p->pid, p->devep)) {
         return usb_host_handle_iso_data(s, p, p->pid == USB_TOKEN_IN);
     }
 
-    rem = p->len;
-    pbuf = p->data;
-    p->len = 0;
+    v = 0;
+    prem = p->iov.iov[v].iov_len;
+    pbuf = p->iov.iov[v].iov_base;
+    rem = p->iov.size;
     while (rem) {
+        if (prem == 0) {
+            v++;
+            assert(v < p->iov.niov);
+            prem = p->iov.iov[v].iov_len;
+            pbuf = p->iov.iov[v].iov_base;
+            assert(prem <= rem);
+        }
         aurb = async_alloc(s);
         aurb->packet = p;
 
@@ -746,31 +895,36 @@ static int usb_host_handle_data(USBDevic
         urb->type          = USBDEVFS_URB_TYPE_BULK;
         urb->usercontext   = s;
         urb->buffer        = pbuf;
+        urb->buffer_length = prem;
 
-        if (rem > MAX_USBFS_BUFFER_SIZE) {
+        if (urb->buffer_length > MAX_USBFS_BUFFER_SIZE) {
             urb->buffer_length = MAX_USBFS_BUFFER_SIZE;
-            aurb->more         = 1;
-        } else {
-            urb->buffer_length = rem;
-            aurb->more         = 0;
         }
         pbuf += urb->buffer_length;
+        prem -= urb->buffer_length;
         rem  -= urb->buffer_length;
+        if (rem) {
+            aurb->more         = 1;
+        }
 
+        trace_usb_host_urb_submit(s->bus_num, s->addr, aurb,
+                                  urb->buffer_length, aurb->more);
         ret = ioctl(s->fd, USBDEVFS_SUBMITURB, urb);
 
         DPRINTF("husb: data submit: ep 0x%x, len %u, more %d, packet %p, aurb %p\n",
                 urb->endpoint, urb->buffer_length, aurb->more, p, aurb);
 
         if (ret < 0) {
-            DPRINTF("husb: submit failed. errno %d\n", errno);
+            perror("USBDEVFS_SUBMITURB");
             async_free(aurb);
 
             switch(errno) {
             case ETIMEDOUT:
+                trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
                 return USB_RET_NAK;
             case EPIPE:
             default:
+                trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_STALL);
                 return USB_RET_STALL;
             }
         }
@@ -790,23 +944,40 @@ static int ctrl_error(void)
 
 static int usb_host_set_address(USBHostDevice *s, int addr)
 {
-    DPRINTF("husb: ctrl set addr %u\n", addr);
+    trace_usb_host_set_address(s->bus_num, s->addr, addr);
     s->dev.addr = addr;
     return 0;
 }
 
 static int usb_host_set_config(USBHostDevice *s, int config)
 {
+    int ret, first = 1;
+
+    trace_usb_host_set_config(s->bus_num, s->addr, config);
+
     usb_host_release_interfaces(s);
 
-    int ret = ioctl(s->fd, USBDEVFS_SETCONFIGURATION, &config);
+again:
+    ret = ioctl(s->fd, USBDEVFS_SETCONFIGURATION, &config);
 
     DPRINTF("husb: ctrl set config %d ret %d errno %d\n", config, ret, errno);
 
+    if (ret < 0 && errno == EBUSY && first) {
+        /* happens if usb device is in use by host drivers */
+        int count = usb_linux_get_num_interfaces(s);
+        if (count > 0) {
+            DPRINTF("husb: busy -> disconnecting %d interfaces\n", count);
+            usb_host_disconnect_ifaces(s, count);
+            first = 0;
+            goto again;
+        }
+    }
+
     if (ret < 0) {
         return ctrl_error();
     }
     usb_host_claim_interfaces(s, config);
+    usb_linux_update_endp_table(s);
     return 0;
 }
 
@@ -815,9 +986,14 @@ static int usb_host_set_interface(USBHos
     struct usbdevfs_setinterface si;
     int i, ret;
 
+    trace_usb_host_set_interface(s->bus_num, s->addr, iface, alt);
+
     for (i = 1; i <= MAX_ENDPOINTS; i++) {
-        if (is_isoc(s, i)) {
-            usb_host_stop_n_free_iso(s, i);
+        if (is_isoc(s, USB_TOKEN_IN, i)) {
+            usb_host_stop_n_free_iso(s, USB_TOKEN_IN, i);
+        }
+        if (is_isoc(s, USB_TOKEN_OUT, i)) {
+            usb_host_stop_n_free_iso(s, USB_TOKEN_OUT, i);
         }
     }
 
@@ -849,8 +1025,7 @@ static int usb_host_handle_control(USBDe
      */
 
     /* Note request is (bRequestType << 8) | bRequest */
-    DPRINTF("husb: ctrl type 0x%x req 0x%x val 0x%x index %u len %u\n",
-            request >> 8, request & 0xff, value, index, length);
+    trace_usb_host_req_control(s->bus_num, s->addr, request, value, index);
 
     switch (request) {
     case DeviceOutRequest | USB_REQ_SET_ADDRESS:
@@ -890,6 +1065,8 @@ static int usb_host_handle_control(USBDe
 
     urb->usercontext = s;
 
+    trace_usb_host_urb_submit(s->bus_num, s->addr, aurb,
+                              urb->buffer_length, aurb->more);
     ret = ioctl(s->fd, USBDEVFS_SUBMITURB, urb);
 
     DPRINTF("husb: submit ctrl. len %u aurb %p\n", urb->buffer_length, aurb);
@@ -910,51 +1087,6 @@ static int usb_host_handle_control(USBDe
     return USB_RET_ASYNC;
 }
 
-static int usb_linux_get_configuration(USBHostDevice *s)
-{
-    uint8_t configuration;
-    struct usb_ctrltransfer ct;
-    int ret;
-
-    if (usb_fs_type == USB_FS_SYS) {
-        char device_name[32], line[1024];
-        int configuration;
-
-        sprintf(device_name, "%d-%s", s->bus_num, s->port);
-
-        if (!usb_host_read_file(line, sizeof(line), "bConfigurationValue",
-                                device_name)) {
-            goto usbdevfs;
-        }
-        if (sscanf(line, "%d", &configuration) != 1) {
-            goto usbdevfs;
-        }
-        return configuration;
-    }
-
-usbdevfs:
-    ct.bRequestType = USB_DIR_IN;
-    ct.bRequest = USB_REQ_GET_CONFIGURATION;
-    ct.wValue = 0;
-    ct.wIndex = 0;
-    ct.wLength = 1;
-    ct.data = &configuration;
-    ct.timeout = 50;
-
-    ret = ioctl(s->fd, USBDEVFS_CONTROL, &ct);
-    if (ret < 0) {
-        perror("usb_linux_get_configuration");
-        return -1;
-    }
-
-    /* in address state */
-    if (configuration == 0) {
-        return -1;
-    }
-
-    return configuration;
-}
-
 static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
     uint8_t configuration, uint8_t interface)
 {
@@ -1000,16 +1132,19 @@ usbdevfs:
 static int usb_linux_update_endp_table(USBHostDevice *s)
 {
     uint8_t *descriptors;
-    uint8_t devep, type, configuration, alt_interface;
-    int interface, length, i;
+    uint8_t devep, type, alt_interface;
+    int interface, length, i, ep, pid;
+    struct endp_data *epd;
 
-    for (i = 0; i < MAX_ENDPOINTS; i++)
-        s->endp_table[i].type = INVALID_EP_TYPE;
+    for (i = 0; i < MAX_ENDPOINTS; i++) {
+        s->ep_in[i].type = INVALID_EP_TYPE;
+        s->ep_out[i].type = INVALID_EP_TYPE;
+    }
 
-    i = usb_linux_get_configuration(s);
-    if (i < 0)
-        return 1;
-    configuration = i;
+    if (s->configuration == 0) {
+        /* not configured yet -- leave all endpoints disabled */
+        return 0;
+    }
 
     /* get the desired configuration, interface, and endpoint descriptors
      * from device description */
@@ -1017,14 +1152,18 @@ static int usb_linux_update_endp_table(U
     length = s->descr_len - 18;
     i = 0;
 
-    if (descriptors[i + 1] != USB_DT_CONFIG ||
-        descriptors[i + 5] != configuration) {
-        DPRINTF("invalid descriptor data - configuration\n");
-        return 1;
-    }
-    i += descriptors[i];
-
     while (i < length) {
+        if (descriptors[i + 1] != USB_DT_CONFIG) {
+            fprintf(stderr, "invalid descriptor data\n");
+            return 1;
+        } else if (descriptors[i + 5] != s->configuration) {
+            DPRINTF("not requested configuration %d\n", s->configuration);
+            i += (descriptors[i + 3] << 8) + descriptors[i + 2];
+            continue;
+        }
+
+        i += descriptors[i];
+
         if (descriptors[i + 1] != USB_DT_INTERFACE ||
             (descriptors[i + 1] == USB_DT_INTERFACE &&
              descriptors[i + 4] == 0)) {
@@ -1033,7 +1172,8 @@ static int usb_linux_update_endp_table(U
         }
 
         interface = descriptors[i + 2];
-        alt_interface = usb_linux_get_alt_setting(s, configuration, interface);
+        alt_interface = usb_linux_get_alt_setting(s, s->configuration,
+                                                  interface);
 
         /* the current interface descriptor is the active interface
          * and has endpoints */
@@ -1056,7 +1196,9 @@ static int usb_linux_update_endp_table(U
             }
 
             devep = descriptors[i + 2];
-            if ((devep & 0x0f) == 0) {
+            pid = (devep & USB_DIR_IN) ? USB_TOKEN_IN : USB_TOKEN_OUT;
+            ep = devep & 0xf;
+            if (ep == 0) {
                 fprintf(stderr, "usb-linux: invalid ep descriptor, ep == 0\n");
                 return 1;
             }
@@ -1067,7 +1209,7 @@ static int usb_linux_update_endp_table(U
                 break;
             case 0x01:
                 type = USBDEVFS_URB_TYPE_ISO;
-                set_max_packet_size(s, (devep & 0xf), descriptors + i);
+                set_max_packet_size(s, pid, ep, descriptors + i);
                 break;
             case 0x02:
                 type = USBDEVFS_URB_TYPE_BULK;
@@ -1079,8 +1221,10 @@ static int usb_linux_update_endp_table(U
                 DPRINTF("usb_host: malformed endpoint type\n");
                 type = USBDEVFS_URB_TYPE_BULK;
             }
-            s->endp_table[(devep & 0xf) - 1].type = type;
-            s->endp_table[(devep & 0xf) - 1].halted = 0;
+            epd = get_endp(s, pid, ep);
+            assert(epd->type == INVALID_EP_TYPE);
+            epd->type = type;
+            epd->halted = 0;
 
             i += descriptors[i];
         }
@@ -1125,15 +1269,17 @@ static int usb_linux_full_speed_compat(U
 }
 
 static int usb_host_open(USBHostDevice *dev, int bus_num,
-                        int addr, char *port, const char *prod_name, int speed)
+                         int addr, const char *port,
+                         const char *prod_name, int speed)
 {
     int fd = -1, ret;
     char buf[1024];
 
+    trace_usb_host_open_started(bus_num, addr);
+
     if (dev->fd != -1) {
         goto fail;
     }
-    printf("husb: open device %d.%d\n", bus_num, addr);
 
     if (!usb_host_device_path) {
         perror("husb: USB Host Device Path not set");
@@ -1172,13 +1318,8 @@ static int usb_host_open(USBHostDevice *
 #endif
 
 
-    /*
-     * Initial configuration is -1 which makes us claim first
-     * available config. We used to start with 1, which does not
-     * always work. I've seen devices where first config starts
-     * with 2.
-     */
-    if (!usb_host_claim_interfaces(dev, -1)) {
+    /* start unconfigured -- we'll wait for the guest to set a configuration */
+    if (!usb_host_claim_interfaces(dev, 0)) {
         goto fail;
     }
 
@@ -1208,7 +1349,7 @@ static int usb_host_open(USBHostDevice *
         dev->dev.speedmask |= USB_SPEED_MASK_FULL;
     }
 
-    printf("husb: grabbed usb device %d.%d\n", bus_num, addr);
+    trace_usb_host_open_success(bus_num, addr);
 
     if (!prod_name || prod_name[0] == '\0') {
         snprintf(dev->dev.product_desc, sizeof(dev->dev.product_desc),
@@ -1229,6 +1370,7 @@ static int usb_host_open(USBHostDevice *
     return 0;
 
 fail:
+    trace_usb_host_open_failure(bus_num, addr);
     if (dev->fd != -1) {
         close(dev->fd);
         dev->fd = -1;
@@ -1240,21 +1382,28 @@ static int usb_host_close(USBHostDevice 
 {
     int i;
 
-    if (dev->fd == -1 || !dev->dev.attached) {
+    if (dev->fd == -1) {
         return -1;
     }
 
+    trace_usb_host_close(dev->bus_num, dev->addr);
+
     qemu_set_fd_handler(dev->fd, NULL, NULL, NULL);
     dev->closing = 1;
     for (i = 1; i <= MAX_ENDPOINTS; i++) {
-        if (is_isoc(dev, i)) {
-            usb_host_stop_n_free_iso(dev, i);
+        if (is_isoc(dev, USB_TOKEN_IN, i)) {
+            usb_host_stop_n_free_iso(dev, USB_TOKEN_IN, i);
+        }
+        if (is_isoc(dev, USB_TOKEN_OUT, i)) {
+            usb_host_stop_n_free_iso(dev, USB_TOKEN_OUT, i);
         }
     }
     async_complete(dev);
     dev->closing = 0;
-    usb_device_detach(&dev->dev);
-    ioctl(dev->fd, USBDEVFS_RESET);
+    if (dev->dev.attached) {
+        usb_device_detach(&dev->dev);
+    }
+    usb_host_do_reset(dev);
     close(dev->fd);
     dev->fd = -1;
     return 0;
@@ -1264,8 +1413,9 @@ static void usb_host_exit_notifier(struc
 {
     USBHostDevice *s = container_of(n, USBHostDevice, exit);
 
+    usb_host_release_port(s);
     if (s->fd != -1) {
-        ioctl(s->fd, USBDEVFS_RESET);
+        usb_host_do_reset(s);;
     }
 }
 
@@ -1275,17 +1425,29 @@ static int usb_host_initfn(USBDevice *de
 
     dev->auto_attach = 0;
     s->fd = -1;
+    s->hub_fd = -1;
+
     QTAILQ_INSERT_TAIL(&hostdevs, s, next);
     s->exit.notify = usb_host_exit_notifier;
     qemu_add_exit_notifier(&s->exit);
     usb_host_auto_check(NULL);
+
+    if (s->match.bus_num != 0 && s->match.port != NULL) {
+        usb_host_claim_port(s);
+    }
     return 0;
 }
 
+static const VMStateDescription vmstate_usb_host = {
+    .name = "usb-host",
+    .unmigratable = 1,
+};
+
 static struct USBDeviceInfo usb_host_dev_info = {
     .product_desc   = "USB Host Device",
     .qdev.name      = "usb-host",
     .qdev.size      = sizeof(USBHostDevice),
+    .qdev.vmsd      = &vmstate_usb_host,
     .init           = usb_host_initfn,
     .handle_packet  = usb_generic_handle_packet,
     .cancel_packet  = usb_host_async_cancel,
@@ -1411,7 +1573,8 @@ static int usb_host_scan_dev(void *opaqu
     FILE *f = NULL;
     char line[1024];
     char buf[1024];
-    int bus_num, addr, speed, device_count, class_id, product_id, vendor_id;
+    int bus_num, addr, speed, device_count;
+    int class_id, product_id, vendor_id, port;
     char product_name[512];
     int ret = 0;
 
@@ -1427,7 +1590,7 @@ static int usb_host_scan_dev(void *opaqu
     }
 
     device_count = 0;
-    bus_num = addr = class_id = product_id = vendor_id = 0;
+    bus_num = addr = class_id = product_id = vendor_id = port = 0;
     speed = -1; /* Can't get the speed from /[proc|dev]/bus/usb/devices */
     for(;;) {
         if (fgets(line, sizeof(line), f) == NULL) {
@@ -1439,7 +1602,12 @@ static int usb_host_scan_dev(void *opaqu
         if (line[0] == 'T' && line[1] == ':') {
             if (device_count && (vendor_id || product_id)) {
                 /* New device.  Add the previously discovered device.  */
-                ret = func(opaque, bus_num, addr, 0, class_id, vendor_id,
+                if (port > 0) {
+                    snprintf(buf, sizeof(buf), "%d", port);
+                } else {
+                    snprintf(buf, sizeof(buf), "?");
+                }
+                ret = func(opaque, bus_num, addr, buf, class_id, vendor_id,
                            product_id, product_name, speed);
                 if (ret) {
                     goto the_end;
@@ -1449,6 +1617,10 @@ static int usb_host_scan_dev(void *opaqu
                 goto fail;
             }
             bus_num = atoi(buf);
+            if (get_tag_value(buf, sizeof(buf), line, "Port=", " ") < 0) {
+                goto fail;
+            }
+            port = atoi(buf);
             if (get_tag_value(buf, sizeof(buf), line, "Dev#=", " ") < 0) {
                 goto fail;
             }
@@ -1494,7 +1666,12 @@ static int usb_host_scan_dev(void *opaqu
     }
     if (device_count && (vendor_id || product_id)) {
         /* Add the last device.  */
-        ret = func(opaque, bus_num, addr, 0, class_id, vendor_id,
+        if (port > 0) {
+            snprintf(buf, sizeof(buf), "%d", port);
+        } else {
+            snprintf(buf, sizeof(buf), "?");
+        }
+        ret = func(opaque, bus_num, addr, buf, class_id, vendor_id,
                    product_id, product_name, speed);
     }
  the_end:
@@ -1678,7 +1855,7 @@ static int usb_host_scan(void *opaque, U
         }
 
         /* the module setting (used later for opening devices) */
-        usb_host_device_path = qemu_mallocz(strlen(devpath)+1);
+        usb_host_device_path = g_malloc0(strlen(devpath)+1);
         strcpy(usb_host_device_path, devpath);
         if (mon) {
             monitor_printf(mon, "husb: using %s file-system with %s\n",
@@ -1703,7 +1880,8 @@ static int usb_host_scan(void *opaque, U
 
 static QEMUTimer *usb_auto_timer;
 
-static int usb_host_auto_scan(void *opaque, int bus_num, int addr, char *port,
+static int usb_host_auto_scan(void *opaque, int bus_num,
+                              int addr, const char *port,
                               int class_id, int vendor_id, int product_id,
                               const char *product_name, int speed)
 {
@@ -1735,6 +1913,10 @@ static int usb_host_auto_scan(void *opaq
             continue;
         }
         /* We got a match */
+        s->seen++;
+        if (s->errcount >= 3) {
+            return 0;
+        }
 
         /* Already attached ? */
         if (s->fd != -1) {
@@ -1742,7 +1924,9 @@ static int usb_host_auto_scan(void *opaq
         }
         DPRINTF("husb: auto open: bus_num %d addr %d\n", bus_num, addr);
 
-        usb_host_open(s, bus_num, addr, port, product_name, speed);
+        if (usb_host_open(s, bus_num, addr, port, product_name, speed) < 0) {
+            s->errcount++;
+        }
         break;
     }
 
@@ -1760,12 +1944,17 @@ static void usb_host_auto_check(void *un
         if (s->fd == -1) {
             unconnected++;
         }
+        if (s->seen == 0) {
+            s->errcount = 0;
+        }
+        s->seen = 0;
     }
 
     if (unconnected == 0) {
         /* nothing to watch */
         if (usb_auto_timer) {
             qemu_del_timer(usb_auto_timer);
+            trace_usb_host_auto_scan_disabled();
         }
         return;
     }
@@ -1775,6 +1964,7 @@ static void usb_host_auto_check(void *un
         if (!usb_auto_timer) {
             return;
         }
+        trace_usb_host_auto_scan_enabled();
     }
     qemu_mod_timer(usb_auto_timer, qemu_get_clock_ms(rt_clock) + 2000);
 }
@@ -1865,7 +2055,8 @@ static const char *usb_class_str(uint8_t
     return p->class_name;
 }
 
-static void usb_info_device(Monitor *mon, int bus_num, int addr, char *port,
+static void usb_info_device(Monitor *mon, int bus_num,
+                            int addr, const char *port,
                             int class_id, int vendor_id, int product_id,
                             const char *product_name,
                             int speed)
@@ -1906,7 +2097,7 @@ static void usb_info_device(Monitor *mon
 }
 
 static int usb_host_info_device(void *opaque, int bus_num, int addr,
-                                char *path, int class_id,
+                                const char *path, int class_id,
                                 int vendor_id, int product_id,
                                 const char *product_name,
                                 int speed)