diff --git a/nimble/host/include/host/ble_hs_iso.h b/nimble/host/include/host/ble_hs_iso.h
index 4588b1bce..07328e83e 100644
--- a/nimble/host/include/host/ble_hs_iso.h
+++ b/nimble/host/include/host/ble_hs_iso.h
@@ -16,7 +16,7 @@
 extern "C" {
 #endif
 
-int ble_hs_hci_set_iso_buf_sz(uint16_t pktlen, uint16_t max_pkts);
+int ble_hs_hci_set_iso_buf_sz(uint16_t pktlen, uint8_t max_pkts);
 
 void ble_hs_hci_add_iso_avail_pkts(uint16_t conn_handle, uint16_t delta);
 
@@ -25,7 +25,7 @@ int ble_hs_hci_iso_tx(uint16_t conn_handle, const uint8_t *sdu, uint16_t sdu_len
 
 typedef int (*ble_hs_iso_pkt_rx_fn)(const uint8_t *data, uint16_t len, void *arg);
 
-int ble_hs_iso_pkt_rx_cb_set(void *cb);
+int ble_hs_iso_pkt_rx_cb_set(ble_hs_iso_pkt_rx_fn cb);
 
 int ble_hs_rx_iso_data(const uint8_t *data, uint16_t len, void *arg);
 
diff --git a/nimble/host/src/ble_hs_iso.c b/nimble/host/src/ble_hs_iso.c
index 6741f63d0..0c2f46e0b 100644
--- a/nimble/host/src/ble_hs_iso.c
+++ b/nimble/host/src/ble_hs_iso.c
@@ -13,6 +13,9 @@
 #include "ble_hs_priv.h"
 #include "bt_osi_mem.h"
 #include "host/ble_hs_iso.h"
+#if MYNEWT_VAL(BLE_STATIC_TO_DYNAMIC)
+#include "esp_nimble_mem.h"
+#endif /* MYNEWT_VAL(BLE_STATIC_TO_DYNAMIC) */
 
 extern int ble_hci_trans_hs_iso_tx(const uint8_t *data, uint16_t length, void *arg);
 #if MYNEWT_VAL(BLE_ISO_NON_STD_FLOW_CTRL)
@@ -39,7 +42,7 @@ _Static_assert((MYNEWT_VAL(BLE_ISO_STD_FLOW_CTRL) &&
 #endif
 
 static uint16_t ble_hs_iso_buf_sz;
-static uint16_t ble_hs_iso_max_pkts;
+static uint8_t ble_hs_iso_max_pkts;
 
 #if MYNEWT_VAL(BLE_ISO_STD_FLOW_CTRL)
 /* Number of available ISO transmit buffers on the controller.
@@ -49,7 +52,7 @@ static uint16_t ble_hs_iso_avail_pkts;
 #endif /* MYNEWT_VAL(BLE_ISO_STD_FLOW_CTRL) */
 
 int
-ble_hs_hci_set_iso_buf_sz(uint16_t pktlen, uint16_t max_pkts)
+ble_hs_hci_set_iso_buf_sz(uint16_t pktlen, uint8_t max_pkts)
 {
     BLE_HS_DBG_ASSERT(ble_hs_locked_by_cur_task());
 
@@ -190,10 +193,12 @@ ble_hs_hci_iso_tx_now(uint16_t conn_handle, const uint8_t *sdu, uint16_t sdu_len
 
     dlh_len = (ts_flag ? BLE_HCI_ISO_DATA_LOAD_TS_SZ : 0) + BLE_HCI_ISO_DATA_LOAD_HDR_SZ;
 
-    if (sdu_len + dlh_len > ble_hs_iso_buf_sz) {
-        return BLE_HS_EMSGSIZE;
-    }
-
+    /* Note:
+     * Here we allocate memory to hold the whole SDU, and in the BLE Controller,
+     * the SDU will be checked. If it's too large, error will be returned.
+     * If the SDU is fine, it will be splitted into one or more PDUs based on
+     * the corresponding ISO parameters.
+     */
     frag = nimble_platform_mem_calloc(1,BLE_HCI_ISO_DATA_HDR_SZ + dlh_len + sdu_len);
     if (frag == NULL) {
         return BLE_HS_ENOMEM;
@@ -204,8 +209,10 @@ ble_hs_hci_iso_tx_now(uint16_t conn_handle, const uint8_t *sdu, uint16_t sdu_len
 
     memcpy(frag + BLE_HCI_ISO_DATA_HDR_SZ + dlh_len, sdu, sdu_len);
 
+    /* Note:
+     * The allocated frag will be freed in the BLE Controller!
+     */
     rc = ble_hci_trans_hs_iso_tx(frag, BLE_HCI_ISO_DATA_HDR_SZ + dlh_len + sdu_len, NULL);
-    nimble_platform_mem_free(frag);
     if (rc) {
         return BLE_HS_EDONE;
     }
diff --git a/nimble/host/src/ble_hs_iso_hci.c b/nimble/host/src/ble_hs_iso_hci.c
index fb02f177e..f58ec7db8 100644
--- a/nimble/host/src/ble_hs_iso_hci.c
+++ b/nimble/host/src/ble_hs_iso_hci.c
@@ -85,12 +85,11 @@ ble_hs_hci_read_local_supp_controller_delay(uint8_t coding_fmt, uint16_t company
     cmd = (void *)cmd_buf;
 
     cmd->coding_fmt = coding_fmt;
-    put_le16(&cmd->company_id, company_id);
-    put_le16(&cmd->vs_codec_id, vs_codec_id);
+    cmd->company_id = company_id;
+    cmd->vs_codec_id = vs_codec_id;
     cmd->logical_tpt_type = logical_transport_type;
     cmd->direction = direction;
     cmd->codec_cfg_len = codec_cfg_len;
-
     if (codec_cfg_len > 0) {
          memcpy(cmd->codec_cfg, codec_cfg, codec_cfg_len);
     }
@@ -187,14 +186,7 @@ ble_hs_hci_read_iso_tx_sync(uint16_t conn_handle, uint16_t *packet_seq_num,
 
     *packet_seq_num = le16toh(rsp.packet_seq_num);
     *timestamp = le32toh(rsp.tx_timestamp);
-    /* Extract 24-bit signed Time_Offset and sign-extend to 32-bit */
-    {
-        int32_t val = rsp.time_offset[0] | (rsp.time_offset[1] << 8) | (rsp.time_offset[2] << 16);
-        if (val & 0x800000) {
-            val |= 0xFF000000;
-        }
-        *timeoffset = (uint32_t)val;
-    }
+    *timeoffset = get_le24(rsp.time_offset);
 
     return 0;
 }