diff --git a/bt-host.c b/bt-host.c
index 2f8f631c25..b73a44d07d 100644
--- a/bt-host.c
+++ b/bt-host.c
@@ -43,7 +43,7 @@ struct bt_host_hci_s {
 };
 
 static void bt_host_send(struct HCIInfo *hci,
-                int type, const uint8_t *data, int len)
+                int type, const uint8_t *data, size_t len)
 {
     struct bt_host_hci_s *s = (struct bt_host_hci_s *) hci;
     uint8_t pkt = type;
@@ -63,17 +63,17 @@ static void bt_host_send(struct HCIInfo *hci,
     }
 }
 
-static void bt_host_cmd(struct HCIInfo *hci, const uint8_t *data, int len)
+static void bt_host_cmd(struct HCIInfo *hci, const uint8_t *data, size_t len)
 {
     bt_host_send(hci, HCI_COMMAND_PKT, data, len);
 }
 
-static void bt_host_acl(struct HCIInfo *hci, const uint8_t *data, int len)
+static void bt_host_acl(struct HCIInfo *hci, const uint8_t *data, size_t len)
 {
     bt_host_send(hci, HCI_ACLDATA_PKT, data, len);
 }
 
-static void bt_host_sco(struct HCIInfo *hci, const uint8_t *data, int len)
+static void bt_host_sco(struct HCIInfo *hci, const uint8_t *data, size_t len)
 {
     bt_host_send(hci, HCI_SCODATA_PKT, data, len);
 }
diff --git a/bt-vhci.c b/bt-vhci.c
index 9d277c32bf..765773188d 100644
--- a/bt-vhci.c
+++ b/bt-vhci.c
@@ -90,7 +90,7 @@ static void vhci_read(void *opaque)
 }
 
 static void vhci_host_send(void *opaque,
-                int type, const uint8_t *data, int len)
+                int type, const uint8_t *data, size_t len)
 {
     struct bt_vhci_s *s = (struct bt_vhci_s *) opaque;
 #if 0
@@ -113,6 +113,7 @@ static void vhci_host_send(void *opaque,
     static uint8_t buf[4096];
 
     buf[0] = type;
+    assert(len < sizeof(buf));
     memcpy(buf + 1, data, len);
 
     while (write(s->fd, buf, len + 1) < 0)
@@ -125,13 +126,13 @@ static void vhci_host_send(void *opaque,
 }
 
 static void vhci_out_hci_packet_event(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     vhci_host_send(opaque, HCI_EVENT_PKT, data, len);
 }
 
 static void vhci_out_hci_packet_acl(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     vhci_host_send(opaque, HCI_ACLDATA_PKT, data, len);
 }
diff --git a/hw/bt/core.c b/hw/bt/core.c
index 78370e64f5..62720d1663 100644
--- a/hw/bt/core.c
+++ b/hw/bt/core.c
@@ -45,7 +45,7 @@ static void bt_dummy_lmp_disconnect_master(struct bt_link_s *link)
 }
 
 static void bt_dummy_lmp_acl_resp(struct bt_link_s *link,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     error_report("%s: stray ACL response PDU, fixme", __func__);
     exit(-1);
diff --git a/hw/bt/hci-csr.c b/hw/bt/hci-csr.c
index 0341ded50c..26bd516d31 100644
--- a/hw/bt/hci-csr.c
+++ b/hw/bt/hci-csr.c
@@ -103,7 +103,7 @@ static inline void csrhci_fifo_wake(struct csrhci_s *s)
 }
 
 #define csrhci_out_packetz(s, len) memset(csrhci_out_packet(s, len), 0, len)
-static uint8_t *csrhci_out_packet(struct csrhci_s *s, int len)
+static uint8_t *csrhci_out_packet(struct csrhci_s *s, size_t len)
 {
     int off = s->out_start + s->out_len;
 
@@ -112,14 +112,14 @@ static uint8_t *csrhci_out_packet(struct csrhci_s *s, int len)
 
     if (off < FIFO_LEN) {
         if (off + len > FIFO_LEN && (s->out_size = off + len) > FIFO_LEN * 2) {
-            error_report("%s: can't alloc %i bytes", __func__, len);
+            error_report("%s: can't alloc %zu bytes", __func__, len);
             exit(-1);
         }
         return s->outfifo + off;
     }
 
     if (s->out_len > s->out_size) {
-        error_report("%s: can't alloc %i bytes", __func__, len);
+        error_report("%s: can't alloc %zu bytes", __func__, len);
         exit(-1);
     }
 
@@ -127,7 +127,7 @@ static uint8_t *csrhci_out_packet(struct csrhci_s *s, int len)
 }
 
 static inline uint8_t *csrhci_out_packet_csr(struct csrhci_s *s,
-                int type, int len)
+                int type, size_t len)
 {
     uint8_t *ret = csrhci_out_packetz(s, len + 2);
 
@@ -138,7 +138,7 @@ static inline uint8_t *csrhci_out_packet_csr(struct csrhci_s *s,
 }
 
 static inline uint8_t *csrhci_out_packet_event(struct csrhci_s *s,
-                int evt, int len)
+                int evt, size_t len)
 {
     uint8_t *ret = csrhci_out_packetz(s,
                     len + 1 + sizeof(struct hci_event_hdr));
@@ -151,7 +151,7 @@ static inline uint8_t *csrhci_out_packet_event(struct csrhci_s *s,
 }
 
 static void csrhci_in_packet_vendor(struct csrhci_s *s, int ocf,
-                uint8_t *data, int len)
+                uint8_t *data, size_t len)
 {
     int offset;
     uint8_t *rpkt;
@@ -320,18 +320,18 @@ static int csrhci_write(struct Chardev *chr,
     struct csrhci_s *s = (struct csrhci_s *)chr;
     int total = 0;
 
-    if (!s->enable)
+    if (!s->enable || len <= 0)
         return 0;
 
     for (;;) {
         int cnt = MIN(len, s->in_needed - s->in_len);
-        if (cnt) {
-            memcpy(s->inpkt + s->in_len, buf, cnt);
-            s->in_len += cnt;
-            buf += cnt;
-            len -= cnt;
-            total += cnt;
-        }
+        assert(cnt > 0);
+
+        memcpy(s->inpkt + s->in_len, buf, cnt);
+        s->in_len += cnt;
+        buf += cnt;
+        len -= cnt;
+        total += cnt;
 
         if (s->in_len < s->in_needed) {
             break;
@@ -363,7 +363,7 @@ static int csrhci_write(struct Chardev *chr,
 }
 
 static void csrhci_out_hci_packet_event(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     struct csrhci_s *s = (struct csrhci_s *) opaque;
     uint8_t *pkt = csrhci_out_packet(s, (len + 2) & ~1);	/* Align */
@@ -375,7 +375,7 @@ static void csrhci_out_hci_packet_event(void *opaque,
 }
 
 static void csrhci_out_hci_packet_acl(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     struct csrhci_s *s = (struct csrhci_s *) opaque;
     uint8_t *pkt = csrhci_out_packet(s, (len + 2) & ~1);	/* Align */
diff --git a/hw/bt/hci.c b/hw/bt/hci.c
index c6b2cc1d48..c59ccc55b9 100644
--- a/hw/bt/hci.c
+++ b/hw/bt/hci.c
@@ -32,7 +32,7 @@
 
 struct bt_hci_s {
     uint8_t *(*evt_packet)(void *opaque);
-    void (*evt_submit)(void *opaque, int len);
+    void (*evt_submit)(void *opaque, size_t len);
     void *opaque;
     uint8_t evt_buf[256];
 
@@ -62,7 +62,7 @@ struct bt_hci_s {
         struct bt_hci_master_link_s {
             struct bt_link_s *link;
             void (*lmp_acl_data)(struct bt_link_s *link,
-                            const uint8_t *data, int start, int len);
+                            const uint8_t *data, int start, size_t len);
             QEMUTimer *acl_mode_timer;
         } handle[HCI_HANDLES_MAX];
         uint32_t role_bmp;
@@ -434,7 +434,7 @@ static const uint8_t bt_event_reserved_mask[8] = {
 };
 
 
-static void null_hci_send(struct HCIInfo *hci, const uint8_t *data, int len)
+static void null_hci_send(struct HCIInfo *hci, const uint8_t *data, size_t len)
 {
 }
 
@@ -452,13 +452,13 @@ struct HCIInfo null_hci = {
 
 
 static inline uint8_t *bt_hci_event_start(struct bt_hci_s *hci,
-                int evt, int len)
+                int evt, size_t len)
 {
     uint8_t *packet, mask;
     int mask_byte;
 
     if (len > 255) {
-        error_report("%s: HCI event params too long (%ib)", __func__, len);
+        error_report("%s: HCI event params too long (%zub)", __func__, len);
         exit(-1);
     }
 
@@ -475,7 +475,7 @@ static inline uint8_t *bt_hci_event_start(struct bt_hci_s *hci,
 }
 
 static inline void bt_hci_event(struct bt_hci_s *hci, int evt,
-                void *params, int len)
+                void *params, size_t len)
 {
     uint8_t *packet = bt_hci_event_start(hci, evt, len);
 
@@ -500,7 +500,7 @@ static inline void bt_hci_event_status(struct bt_hci_s *hci, int status)
 }
 
 static inline void bt_hci_event_complete(struct bt_hci_s *hci,
-                void *ret, int len)
+                void *ret, size_t len)
 {
     uint8_t *packet = bt_hci_event_start(hci, EVT_CMD_COMPLETE,
                     len + EVT_CMD_COMPLETE_SIZE);
@@ -1477,7 +1477,7 @@ static inline void bt_hci_event_num_comp_pkts(struct bt_hci_s *hci,
 }
 
 static void bt_submit_hci(struct HCIInfo *info,
-                const uint8_t *data, int length)
+                const uint8_t *data, size_t length)
 {
     struct bt_hci_s *hci = hci_from_info(info);
     uint16_t cmd;
@@ -1971,7 +1971,7 @@ static void bt_submit_hci(struct HCIInfo *info,
         break;
 
     short_hci:
-        error_report("%s: HCI packet too short (%iB)", __func__, length);
+        error_report("%s: HCI packet too short (%zuB)", __func__, length);
         bt_hci_event_status(hci, HCI_INVALID_PARAMETERS);
         break;
     }
@@ -1982,7 +1982,7 @@ static void bt_submit_hci(struct HCIInfo *info,
  * know that a packet contained the last fragment of the SDU when the next
  * SDU starts.  */
 static inline void bt_hci_lmp_acl_data(struct bt_hci_s *hci, uint16_t handle,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     struct hci_acl_hdr *pkt = (void *) hci->acl_buf;
 
@@ -1990,7 +1990,7 @@ static inline void bt_hci_lmp_acl_data(struct bt_hci_s *hci, uint16_t handle,
     /* TODO: avoid memcpy'ing */
 
     if (len + HCI_ACL_HDR_SIZE > sizeof(hci->acl_buf)) {
-        error_report("%s: can't take ACL packets %i bytes long",
+        error_report("%s: can't take ACL packets %zu bytes long",
                      __func__, len);
         return;
     }
@@ -2004,7 +2004,7 @@ static inline void bt_hci_lmp_acl_data(struct bt_hci_s *hci, uint16_t handle,
 }
 
 static void bt_hci_lmp_acl_data_slave(struct bt_link_s *btlink,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     struct bt_hci_link_s *link = (struct bt_hci_link_s *) btlink;
 
@@ -2013,14 +2013,14 @@ static void bt_hci_lmp_acl_data_slave(struct bt_link_s *btlink,
 }
 
 static void bt_hci_lmp_acl_data_host(struct bt_link_s *link,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     bt_hci_lmp_acl_data(hci_from_device(link->host),
                     link->handle, data, start, len);
 }
 
 static void bt_submit_acl(struct HCIInfo *info,
-                const uint8_t *data, int length)
+                const uint8_t *data, size_t length)
 {
     struct bt_hci_s *hci = hci_from_info(info);
     uint16_t handle;
@@ -2028,7 +2028,7 @@ static void bt_submit_acl(struct HCIInfo *info,
     struct bt_link_s *link;
 
     if (length < HCI_ACL_HDR_SIZE) {
-        error_report("%s: ACL packet too short (%iB)", __func__, length);
+        error_report("%s: ACL packet too short (%zuB)", __func__, length);
         return;
     }
 
@@ -2046,7 +2046,7 @@ static void bt_submit_acl(struct HCIInfo *info,
     handle &= ~HCI_HANDLE_OFFSET;
 
     if (datalen > length) {
-        error_report("%s: ACL packet too short (%iB < %iB)",
+        error_report("%s: ACL packet too short (%zuB < %iB)",
                      __func__, length, datalen);
         return;
     }
@@ -2088,7 +2088,7 @@ static void bt_submit_acl(struct HCIInfo *info,
 }
 
 static void bt_submit_sco(struct HCIInfo *info,
-                const uint8_t *data, int length)
+                const uint8_t *data, size_t length)
 {
     struct bt_hci_s *hci = hci_from_info(info);
     uint16_t handle;
@@ -2107,7 +2107,7 @@ static void bt_submit_sco(struct HCIInfo *info,
     }
 
     if (datalen > length) {
-        error_report("%s: SCO packet too short (%iB < %iB)",
+        error_report("%s: SCO packet too short (%zuB < %iB)",
                      __func__, length, datalen);
         return;
     }
@@ -2128,7 +2128,7 @@ static uint8_t *bt_hci_evt_packet(void *opaque)
     return s->evt_buf;
 }
 
-static void bt_hci_evt_submit(void *opaque, int len)
+static void bt_hci_evt_submit(void *opaque, size_t len)
 {
     /* TODO: notify upper layer */
     struct bt_hci_s *s = opaque;
diff --git a/hw/bt/hid.c b/hw/bt/hid.c
index 056291f9b5..c5ecc8bdcd 100644
--- a/hw/bt/hid.c
+++ b/hw/bt/hid.c
@@ -96,7 +96,7 @@ struct bt_hid_device_s {
     int data_type;
     int intr_state;
     struct {
-        int len;
+        size_t len;
         uint8_t buffer[1024];
     } dataother, datain, dataout, feature, intrdataout;
     enum {
@@ -169,7 +169,7 @@ static void bt_hid_disconnect(struct bt_hid_device_s *s)
 }
 
 static void bt_hid_send_data(struct bt_l2cap_conn_params_s *ch, int type,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     uint8_t *pkt, hdr = (BT_DATA << 4) | type;
     int plen;
@@ -190,7 +190,7 @@ static void bt_hid_send_data(struct bt_l2cap_conn_params_s *ch, int type,
 }
 
 static void bt_hid_control_transaction(struct bt_hid_device_s *s,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     uint8_t type, parameter;
     int rlen, ret = -1;
@@ -362,7 +362,7 @@ static void bt_hid_control_transaction(struct bt_hid_device_s *s,
         bt_hid_send_handshake(s, ret);
 }
 
-static void bt_hid_control_sdu(void *opaque, const uint8_t *data, int len)
+static void bt_hid_control_sdu(void *opaque, const uint8_t *data, size_t len)
 {
     struct bt_hid_device_s *hid = opaque;
 
@@ -388,7 +388,7 @@ static void bt_hid_datain(HIDState *hs)
                         hid->datain.buffer, hid->datain.len);
 }
 
-static void bt_hid_interrupt_sdu(void *opaque, const uint8_t *data, int len)
+static void bt_hid_interrupt_sdu(void *opaque, const uint8_t *data, size_t len)
 {
     struct bt_hid_device_s *hid = opaque;
 
diff --git a/hw/bt/l2cap.c b/hw/bt/l2cap.c
index 9cf27f0df6..efd9a4b66a 100644
--- a/hw/bt/l2cap.c
+++ b/hw/bt/l2cap.c
@@ -32,10 +32,10 @@ struct l2cap_instance_s {
     int role;
 
     uint8_t frame_in[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4)));
-    int frame_in_len;
+    uint32_t frame_in_len;
 
     uint8_t frame_out[65535 + L2CAP_HDR_SIZE] __attribute__ ((aligned (4)));
-    int frame_out_len;
+    uint32_t frame_out_len;
 
     /* Signalling channel timers.  They exist per-request but we can make
      * sure we have no more than one outstanding request at any time.  */
@@ -49,7 +49,7 @@ struct l2cap_instance_s {
         struct bt_l2cap_conn_params_s params;
 
         void (*frame_in)(struct l2cap_chan_s *chan, uint16_t cid,
-                        const l2cap_hdr *hdr, int len);
+                        const l2cap_hdr *hdr, size_t len);
         int mps;
         int min_mtu;
 
@@ -68,7 +68,7 @@ struct l2cap_instance_s {
 
         /* Only flow-controlled, connection-oriented channels */
         uint8_t sdu[65536]; /* TODO: dynamically allocate */
-        int len_cur, len_total;
+        uint32_t len_cur, len_total;
         int rexmit;
         int monitor_timeout;
         QEMUTimer *monitor_timer;
@@ -140,7 +140,7 @@ static const uint16_t l2cap_fcs16_table[256] = {
     0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040,
 };
 
-static uint16_t l2cap_fcs16(const uint8_t *message, int len)
+static uint16_t l2cap_fcs16(const uint8_t *message, size_t len)
 {
     uint16_t fcs = 0x0000;
 
@@ -186,7 +186,7 @@ static void l2cap_monitor_timer_update(struct l2cap_chan_s *ch)
 }
 
 static void l2cap_command_reject(struct l2cap_instance_s *l2cap, int id,
-                uint16_t reason, const void *data, int plen)
+                uint16_t reason, const void *data, size_t plen)
 {
     uint8_t *pkt;
     l2cap_cmd_hdr *hdr;
@@ -247,7 +247,7 @@ static void l2cap_connection_response(struct l2cap_instance_s *l2cap,
 }
 
 static void l2cap_configuration_request(struct l2cap_instance_s *l2cap,
-                int dcid, int flag, const uint8_t *data, int len)
+                int dcid, int flag, const uint8_t *data, size_t len)
 {
     uint8_t *pkt;
     l2cap_cmd_hdr *hdr;
@@ -275,7 +275,7 @@ static void l2cap_configuration_request(struct l2cap_instance_s *l2cap,
 }
 
 static void l2cap_configuration_response(struct l2cap_instance_s *l2cap,
-                int scid, int flag, int result, const uint8_t *data, int len)
+                int scid, int flag, int result, const uint8_t *data, size_t len)
 {
     uint8_t *pkt;
     l2cap_cmd_hdr *hdr;
@@ -322,7 +322,7 @@ static void l2cap_disconnection_response(struct l2cap_instance_s *l2cap,
 }
 
 static void l2cap_echo_response(struct l2cap_instance_s *l2cap,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     uint8_t *pkt;
     l2cap_cmd_hdr *hdr;
@@ -343,7 +343,7 @@ static void l2cap_echo_response(struct l2cap_instance_s *l2cap,
 }
 
 static void l2cap_info_response(struct l2cap_instance_s *l2cap, int type,
-                int result, const uint8_t *data, int len)
+                int result, const uint8_t *data, size_t len)
 {
     uint8_t *pkt;
     l2cap_cmd_hdr *hdr;
@@ -366,16 +366,18 @@ static void l2cap_info_response(struct l2cap_instance_s *l2cap, int type,
     l2cap->signalling_ch.params.sdu_submit(&l2cap->signalling_ch.params);
 }
 
-static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len);
+static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm,
+                size_t len);
 static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms);
 #if 0
-static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len);
+static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm,
+                size_t len);
 static void l2cap_iframe_submit(struct bt_l2cap_conn_params_s *parm);
 #endif
 static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid,
-                const l2cap_hdr *hdr, int len);
+                const l2cap_hdr *hdr, size_t len);
 static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid,
-                const l2cap_hdr *hdr, int len);
+                const l2cap_hdr *hdr, size_t len);
 
 static int l2cap_cid_new(struct l2cap_instance_s *l2cap)
 {
@@ -499,7 +501,7 @@ static void l2cap_channel_config_req_event(struct l2cap_instance_s *l2cap,
 
 static int l2cap_channel_config(struct l2cap_instance_s *l2cap,
                 struct l2cap_chan_s *ch, int flag,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     l2cap_conf_opt *opt;
     l2cap_conf_opt_qos *qos;
@@ -684,7 +686,7 @@ static int l2cap_channel_config(struct l2cap_instance_s *l2cap,
 }
 
 static void l2cap_channel_config_req_msg(struct l2cap_instance_s *l2cap,
-                int flag, int cid, const uint8_t *data, int len)
+                int flag, int cid, const uint8_t *data, size_t len)
 {
     struct l2cap_chan_s *ch;
 
@@ -716,7 +718,7 @@ static void l2cap_channel_config_req_msg(struct l2cap_instance_s *l2cap,
 }
 
 static int l2cap_channel_config_rsp_msg(struct l2cap_instance_s *l2cap,
-                int result, int flag, int cid, const uint8_t *data, int len)
+                int result, int flag, int cid, const uint8_t *data, size_t len)
 {
     struct l2cap_chan_s *ch;
 
@@ -784,7 +786,7 @@ static void l2cap_info(struct l2cap_instance_s *l2cap, int type)
 }
 
 static void l2cap_command(struct l2cap_instance_s *l2cap, int code, int id,
-                const uint8_t *params, int len)
+                const uint8_t *params, size_t len)
 {
     int err;
 
@@ -939,7 +941,7 @@ static void l2cap_rexmit_enable(struct l2cap_chan_s *ch, int enable)
 }
 
 /* Command frame SDU */
-static void l2cap_cframe_in(void *opaque, const uint8_t *data, int len)
+static void l2cap_cframe_in(void *opaque, const uint8_t *data, size_t len)
 {
     struct l2cap_instance_s *l2cap = opaque;
     const l2cap_cmd_hdr *hdr;
@@ -967,7 +969,7 @@ static void l2cap_cframe_in(void *opaque, const uint8_t *data, int len)
 }
 
 /* Group frame SDU */
-static void l2cap_gframe_in(void *opaque, const uint8_t *data, int len)
+static void l2cap_gframe_in(void *opaque, const uint8_t *data, size_t len)
 {
 }
 
@@ -978,7 +980,7 @@ static void l2cap_sframe_in(struct l2cap_chan_s *ch, uint16_t ctrl)
 
 /* Basic L2CAP mode Information frame */
 static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid,
-                const l2cap_hdr *hdr, int len)
+                const l2cap_hdr *hdr, size_t len)
 {
     /* We have a full SDU, no further processing */
     ch->params.sdu_in(ch->params.opaque, hdr->data, len);
@@ -986,7 +988,7 @@ static void l2cap_bframe_in(struct l2cap_chan_s *ch, uint16_t cid,
 
 /* Flow Control and Retransmission mode frame */
 static void l2cap_iframe_in(struct l2cap_chan_s *ch, uint16_t cid,
-                const l2cap_hdr *hdr, int len)
+                const l2cap_hdr *hdr, size_t len)
 {
     uint16_t fcs = lduw_le_p(hdr->data + len - 2);
 
@@ -1077,7 +1079,7 @@ static void l2cap_frame_in(struct l2cap_instance_s *l2cap,
 
 /* "Recombination" */
 static void l2cap_pdu_in(struct l2cap_instance_s *l2cap,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     const l2cap_hdr *hdr = (void *) l2cap->frame_in;
 
@@ -1124,7 +1126,7 @@ static inline void l2cap_pdu_submit(struct l2cap_instance_s *l2cap)
             (l2cap->link, l2cap->frame_out, 1, l2cap->frame_out_len);
 }
 
-static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, int len)
+static uint8_t *l2cap_bframe_out(struct bt_l2cap_conn_params_s *parm, size_t len)
 {
     struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm;
 
@@ -1147,7 +1149,7 @@ static void l2cap_bframe_submit(struct bt_l2cap_conn_params_s *parms)
 
 #if 0
 /* Stub: Only used if an emulated device requests outgoing flow control */
-static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, int len)
+static uint8_t *l2cap_iframe_out(struct bt_l2cap_conn_params_s *parm, size_t len)
 {
     struct l2cap_chan_s *chan = (struct l2cap_chan_s *) parm;
 
@@ -1292,7 +1294,7 @@ static void l2cap_lmp_disconnect_slave(struct bt_link_s *link)
 }
 
 static void l2cap_lmp_acl_data_slave(struct bt_link_s *link,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     struct slave_l2cap_instance_s *l2cap =
             (struct slave_l2cap_instance_s *) link;
@@ -1305,7 +1307,7 @@ static void l2cap_lmp_acl_data_slave(struct bt_link_s *link,
 
 /* Stub */
 static void l2cap_lmp_acl_data_host(struct bt_link_s *link,
-                const uint8_t *data, int start, int len)
+                const uint8_t *data, int start, size_t len)
 {
     struct bt_l2cap_device_s *dev = (struct bt_l2cap_device_s *) link->host;
     struct l2cap_instance_s *l2cap =
diff --git a/hw/bt/sdp.c b/hw/bt/sdp.c
index f4aba9d74f..163d315874 100644
--- a/hw/bt/sdp.c
+++ b/hw/bt/sdp.c
@@ -497,7 +497,7 @@ static ssize_t sdp_svc_search_attr_get(struct bt_l2cap_sdp_state_s *sdp,
     return end + 2;
 }
 
-static void bt_l2cap_sdp_sdu_in(void *opaque, const uint8_t *data, int len)
+static void bt_l2cap_sdp_sdu_in(void *opaque, const uint8_t *data, size_t len)
 {
     struct bt_l2cap_sdp_state_s *sdp = opaque;
     enum bt_sdp_cmd pdu_id;
@@ -507,7 +507,7 @@ static void bt_l2cap_sdp_sdu_in(void *opaque, const uint8_t *data, int len)
     int rsp_len = 0;
 
     if (len < 5) {
-        error_report("%s: short SDP PDU (%iB).", __func__, len);
+        error_report("%s: short SDP PDU (%zuB).", __func__, len);
         return;
     }
 
@@ -518,7 +518,7 @@ static void bt_l2cap_sdp_sdu_in(void *opaque, const uint8_t *data, int len)
     len -= 5;
 
     if (len != plen) {
-        error_report("%s: wrong SDP PDU length (%iB != %iB).",
+        error_report("%s: wrong SDP PDU length (%iB != %zuB).",
                         __func__, plen, len);
         err = SDP_INVALID_PDU_SIZE;
         goto respond;
diff --git a/hw/usb/dev-bluetooth.c b/hw/usb/dev-bluetooth.c
index eac7365b0a..cf46ba06c6 100644
--- a/hw/usb/dev-bluetooth.c
+++ b/hw/usb/dev-bluetooth.c
@@ -265,7 +265,7 @@ static void usb_bt_fifo_reset(struct usb_hci_in_fifo_s *fifo)
 }
 
 static void usb_bt_fifo_enqueue(struct usb_hci_in_fifo_s *fifo,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     int off = fifo->dstart + fifo->dlen;
     uint8_t *buf;
@@ -274,13 +274,13 @@ static void usb_bt_fifo_enqueue(struct usb_hci_in_fifo_s *fifo,
     if (off <= DFIFO_LEN_MASK) {
         if (off + len > DFIFO_LEN_MASK + 1 &&
                         (fifo->dsize = off + len) > (DFIFO_LEN_MASK + 1) * 2) {
-            fprintf(stderr, "%s: can't alloc %i bytes\n", __func__, len);
+            fprintf(stderr, "%s: can't alloc %zu bytes\n", __func__, len);
             exit(-1);
         }
         buf = fifo->data + off;
     } else {
         if (fifo->dlen > fifo->dsize) {
-            fprintf(stderr, "%s: can't alloc %i bytes\n", __func__, len);
+            fprintf(stderr, "%s: can't alloc %zu bytes\n", __func__, len);
             exit(-1);
         }
         buf = fifo->data + off - fifo->dsize;
@@ -319,7 +319,7 @@ static inline void usb_bt_fifo_dequeue(struct usb_hci_in_fifo_s *fifo,
 
 static inline void usb_bt_fifo_out_enqueue(struct USBBtState *s,
                 struct usb_hci_out_fifo_s *fifo,
-                void (*send)(struct HCIInfo *, const uint8_t *, int),
+                void (*send)(struct HCIInfo *, const uint8_t *, size_t),
                 int (*complete)(const uint8_t *, int),
                 USBPacket *p)
 {
@@ -478,7 +478,7 @@ static void usb_bt_handle_data(USBDevice *dev, USBPacket *p)
 }
 
 static void usb_bt_out_hci_packet_event(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     struct USBBtState *s = (struct USBBtState *) opaque;
 
@@ -489,7 +489,7 @@ static void usb_bt_out_hci_packet_event(void *opaque,
 }
 
 static void usb_bt_out_hci_packet_acl(void *opaque,
-                const uint8_t *data, int len)
+                const uint8_t *data, size_t len)
 {
     struct USBBtState *s = (struct USBBtState *) opaque;
 
diff --git a/include/hw/bt.h b/include/hw/bt.h
index b5e11d4d43..bc362aa662 100644
--- a/include/hw/bt.h
+++ b/include/hw/bt.h
@@ -94,9 +94,9 @@ struct bt_device_s {
     void (*lmp_disconnect_master)(struct bt_link_s *link);
     void (*lmp_disconnect_slave)(struct bt_link_s *link);
     void (*lmp_acl_data)(struct bt_link_s *link, const uint8_t *data,
-                    int start, int len);
+                    int start, size_t len);
     void (*lmp_acl_resp)(struct bt_link_s *link, const uint8_t *data,
-                    int start, int len);
+                    int start, size_t len);
     void (*lmp_mode_change)(struct bt_link_s *link);
 
     void (*handle_destroy)(struct bt_device_s *device);
@@ -148,12 +148,12 @@ struct bt_l2cap_device_s {
 
 struct bt_l2cap_conn_params_s {
     /* Input */
-    uint8_t *(*sdu_out)(struct bt_l2cap_conn_params_s *chan, int len);
+    uint8_t *(*sdu_out)(struct bt_l2cap_conn_params_s *chan, size_t len);
     void (*sdu_submit)(struct bt_l2cap_conn_params_s *chan);
     int remote_mtu;
     /* Output */
     void *opaque;
-    void (*sdu_in)(void *opaque, const uint8_t *data, int len);
+    void (*sdu_in)(void *opaque, const uint8_t *data, size_t len);
     void (*close)(void *opaque);
 };
 
diff --git a/include/sysemu/bt.h b/include/sysemu/bt.h
index ddb05cd109..db935c695d 100644
--- a/include/sysemu/bt.h
+++ b/include/sysemu/bt.h
@@ -5,12 +5,12 @@
 
 struct HCIInfo {
     int (*bdaddr_set)(struct HCIInfo *hci, const uint8_t *bd_addr);
-    void (*cmd_send)(struct HCIInfo *hci, const uint8_t *data, int len);
-    void (*sco_send)(struct HCIInfo *hci, const uint8_t *data, int len);
-    void (*acl_send)(struct HCIInfo *hci, const uint8_t *data, int len);
+    void (*cmd_send)(struct HCIInfo *hci, const uint8_t *data, size_t len);
+    void (*sco_send)(struct HCIInfo *hci, const uint8_t *data, size_t len);
+    void (*acl_send)(struct HCIInfo *hci, const uint8_t *data, size_t len);
     void *opaque;
-    void (*evt_recv)(void *opaque, const uint8_t *data, int len);
-    void (*acl_recv)(void *opaque, const uint8_t *data, int len);
+    void (*evt_recv)(void *opaque, const uint8_t *data, size_t len);
+    void (*acl_recv)(void *opaque, const uint8_t *data, size_t len);
 };
 
 /* bt-host.c */
