esp32/network_ppp: Use non-thread-safe API inside status callback.

The status callback runs on the lwIP tcpip_thread, and thus must use the
non-thread-safe API because the thread-safe API would cause a deadlock.

Signed-off-by: Daniël van de Giessen <daniel@dvdgiessen.nl>

2 files changed, 13 insertions, 6 deletions

diff --git a/extmod/network_ppp_lwip.c b/extmod/network_ppp_lwip.c
index 2c3dac920..883275f48 100644
--- a/extmod/network_ppp_lwip.c
+++ b/extmod/network_ppp_lwip.c
@@ -62,8 +62,6 @@ typedef struct _network_ppp_obj_t {
 
 const mp_obj_type_t mp_network_ppp_lwip_type;
 
-static mp_obj_t network_ppp___del__(mp_obj_t self_in);
-
 static void network_ppp_stream_uart_irq_disable(network_ppp_obj_t *self) {
     if (self->stream == mp_const_none) {
         return;
@@ -88,8 +86,12 @@ static void network_ppp_status_cb(ppp_pcb *pcb, int err_code, void *ctx) {
                 // only need to free the PPP PCB, not close it.
                 self->state = STATE_ACTIVE;
             }
+            network_ppp_stream_uart_irq_disable(self);
             // Clean up the PPP PCB.
-            network_ppp___del__(MP_OBJ_FROM_PTR(self));
+            if (ppp_free(pcb) == ERR_OK) {
+                self->state = STATE_INACTIVE;
+                self->pcb = NULL;
+            }
             break;
         default:
             self->state = STATE_ERROR;
diff --git a/ports/esp32/network_ppp.c b/ports/esp32/network_ppp.c
index 77e4385ca..3a9cb239d 100644
--- a/ports/esp32/network_ppp.c
+++ b/ports/esp32/network_ppp.c
@@ -68,8 +68,6 @@ typedef struct _network_ppp_obj_t {
 
 const mp_obj_type_t esp_network_ppp_lwip_type;
 
-static mp_obj_t network_ppp___del__(mp_obj_t self_in);
-
 static void network_ppp_stream_uart_irq_disable(network_ppp_obj_t *self) {
     if (self->stream == mp_const_none) {
         return;
@@ -94,8 +92,15 @@ static void network_ppp_status_cb(ppp_pcb *pcb, int err_code, void *ctx) {
                 // only need to free the PPP PCB, not close it.
                 self->state = STATE_ACTIVE;
             }
+            network_ppp_stream_uart_irq_disable(self);
             // Clean up the PPP PCB.
-            network_ppp___del__(MP_OBJ_FROM_PTR(self));
+            // Note: Because we use pppapi_close instead of ppp_close, this
+            // callback will run on the lwIP tcpip_thread, thus to prevent a
+            // deadlock we must use the non-threadsafe function here.
+            if (ppp_free(pcb) == ERR_OK) {
+                self->state = STATE_INACTIVE;
+                self->pcb = NULL;
+            }
             break;
         default:
             self->state = STATE_ERROR;