diff --git a/ports/raspberrypi/common-hal/socketpool/Socket.c b/ports/raspberrypi/common-hal/socketpool/Socket.c
index 37c37445de..71a31379ad 100644
--- a/ports/raspberrypi/common-hal/socketpool/Socket.c
+++ b/ports/raspberrypi/common-hal/socketpool/Socket.c
@@ -504,6 +504,11 @@ STATIC mp_uint_t lwip_tcp_send(socketpool_socket_obj_t *socket, const byte *buf,
         if (err != ERR_MEM) {
             break;
         }
+        if (err == ERR_MEM && write_len > TCP_MSS) {
+            // Decreasing the amount sent to the next lower number of MSS
+            write_len = (write_len - 1) / TCP_MSS * TCP_MSS;
+            continue;
+        }
         err = tcp_output(socket->pcb.tcp);
         if (err != ERR_OK) {
             break;
diff --git a/ports/raspberrypi/common-hal/wifi/Radio.c b/ports/raspberrypi/common-hal/wifi/Radio.c
index f5d4983dcb..498ec862b2 100644
--- a/ports/raspberrypi/common-hal/wifi/Radio.c
+++ b/ports/raspberrypi/common-hal/wifi/Radio.c
@@ -158,6 +158,13 @@ void common_hal_wifi_radio_start_station(wifi_radio_obj_t *self) {
 }
 
 void common_hal_wifi_radio_stop_station(wifi_radio_obj_t *self) {
+    cyw43_wifi_leave(&cyw43_state, CYW43_ITF_STA);
+    // This is wrong, but without this call the state of ITF_STA is still
+    // reported as CYW43_LINK_JOIN (by wifi_link_status) and CYW43_LINK_UP
+    // (by tcpip_link_status). Until AP support is added, we can ignore the
+    // problem.
+    cyw43_wifi_leave(&cyw43_state, CYW43_ITF_AP);
+    bindings_cyw43_wifi_enforce_pm();
 }
 
 void common_hal_wifi_radio_start_ap(wifi_radio_obj_t *self, uint8_t *ssid, size_t ssid_len, uint8_t *password, size_t password_len, uint8_t channel, uint8_t authmode, uint8_t max_connections) {
diff --git a/ports/raspberrypi/lwip_inc/lwipopts.h b/ports/raspberrypi/lwip_inc/lwipopts.h
index ac4dd1564b..936a141602 100644
--- a/ports/raspberrypi/lwip_inc/lwipopts.h
+++ b/ports/raspberrypi/lwip_inc/lwipopts.h
@@ -47,6 +47,7 @@
 #define LWIP_TCP                    1
 #define LWIP_UDP                    1
 #define LWIP_DNS                    1
+#define LWIP_DNS_SUPPORT_MDNS_QUERIES   1
 #define LWIP_TCP_KEEPALIVE          1
 #define LWIP_NETIF_TX_SINGLE_PBUF   1
 #define DHCP_DOES_ARP_CHECK         0
@@ -91,4 +92,13 @@
 
 #define LWIP_NO_CTYPE_H 1
 
+#define X8_F  "02x"
+#define U16_F "u"
+#define U32_F "lu"
+#define S32_F "ld"
+#define X32_F "lx"
+
+#define S16_F "d"
+#define X16_F "x"
+#define SZT_F "u"
 #endif /* __LWIPOPTS_H__ */
diff --git a/shared-bindings/socketpool/Socket.c b/shared-bindings/socketpool/Socket.c
index 7f0d870771..89b23125c5 100644
--- a/shared-bindings/socketpool/Socket.c
+++ b/shared-bindings/socketpool/Socket.c
@@ -37,6 +37,7 @@
 #include "py/mperrno.h"
 
 #include "shared/netutils/netutils.h"
+#include "shared/runtime/interrupt_char.h"
 
 //| class Socket:
 //|     """TCP, UDP and RAW socket. Cannot be created directly. Instead, call
@@ -255,6 +256,46 @@ STATIC mp_obj_t _socketpool_socket_send(mp_obj_t self_in, mp_obj_t buf_in) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socketpool_socket_send_obj, _socketpool_socket_send);
 
+//|     def sendall(self, bytes: ReadableBuffer) -> None:
+//|         """Send some bytes to the connected remote address.
+//|         Suits sockets of type SOCK_STREAM
+//|
+//|         This calls send() repeatedly until all the data is sent or an error
+//|         occurs. If an error occurs, it's impossible to tell how much data
+//|         has been sent.
+//|
+//|         :param ~bytes bytes: some bytes to send"""
+//|         ...
+STATIC mp_obj_t _socketpool_socket_sendall(mp_obj_t self_in, mp_obj_t buf_in) {
+    socketpool_socket_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    if (common_hal_socketpool_socket_get_closed(self)) {
+        // Bad file number.
+        mp_raise_OSError(MP_EBADF);
+    }
+    if (!common_hal_socketpool_socket_get_connected(self)) {
+        mp_raise_BrokenPipeError();
+    }
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ);
+    while (bufinfo.len > 0) {
+        mp_int_t ret = common_hal_socketpool_socket_send(self, bufinfo.buf, bufinfo.len);
+        if (ret == -1) {
+            mp_raise_BrokenPipeError();
+        }
+        bufinfo.len -= ret;
+        bufinfo.buf += ret;
+        if (bufinfo.len > 0) {
+            RUN_BACKGROUND_TASKS;
+            // Allow user to break out of sendall with a KeyboardInterrupt.
+            if (mp_hal_is_interrupted()) {
+                return 0;
+            }
+        }
+    }
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(socketpool_socket_sendall_obj, _socketpool_socket_sendall);
+
 //|     def sendto(self, bytes: ReadableBuffer, address: Tuple[str, int]) -> int:
 //|         """Send some bytes to a specific address.
 //|         Suits sockets of type SOCK_DGRAM
@@ -372,6 +413,7 @@ STATIC const mp_rom_map_elem_t socketpool_socket_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_recvfrom_into), MP_ROM_PTR(&socketpool_socket_recvfrom_into_obj) },
     { MP_ROM_QSTR(MP_QSTR_recv_into), MP_ROM_PTR(&socketpool_socket_recv_into_obj) },
     { MP_ROM_QSTR(MP_QSTR_send), MP_ROM_PTR(&socketpool_socket_send_obj) },
+    { MP_ROM_QSTR(MP_QSTR_sendall), MP_ROM_PTR(&socketpool_socket_sendall_obj) },
     { MP_ROM_QSTR(MP_QSTR_sendto), MP_ROM_PTR(&socketpool_socket_sendto_obj) },
     { MP_ROM_QSTR(MP_QSTR_setblocking), MP_ROM_PTR(&socketpool_socket_setblocking_obj) },
     // { MP_ROM_QSTR(MP_QSTR_setsockopt), MP_ROM_PTR(&socketpool_socket_setsockopt_obj) },