diff --git a/lib/mp3 b/lib/mp3
index 7a5de1ad777e..aac02afd9f24 160000
--- a/lib/mp3
+++ b/lib/mp3
@@ -1 +1 @@
-Subproject commit 7a5de1ad777e95b0f4fab7bbd35678c7d319b1b5
+Subproject commit aac02afd9f24d2ee930f650156654ab9211a306a
diff --git a/ports/espressif/Makefile b/ports/espressif/Makefile
index 9eed90b71af5..8fb21c953f4e 100644
--- a/ports/espressif/Makefile
+++ b/ports/espressif/Makefile
@@ -152,7 +152,8 @@ CFLAGS += \
 	-DESP_PLATFORM=1 \
 	-DMBEDTLS_CONFIG_FILE=\"mbedtls/esp_config.h\" \
 	-DMBEDTLS_PADLOCK_FILE=\"ports/espressif/esp-idf/components/mbedtls/mbedtls/library/padlock.h\" \
-	-DUNITY_INCLUDE_CONFIG_H -DWITH_POSIX
+	-DUNITY_INCLUDE_CONFIG_H -DWITH_POSIX \
+	-DMP3DEC_GENERIC
 
 # Make our canary value match FreeRTOS's
 # This define is in FreeRTOS as tskSTACK_FILL_BYTE 0xa5U which we expand out to a full word.
@@ -303,7 +304,9 @@ SRC_C += \
 	peripherals/i2c.c \
 	peripherals/$(IDF_TARGET)/pins.c
 
+ifeq ($(CIRCUITPY_SSL),1)
 SRC_C += lib/mbedtls_config/crt_bundle.c
+endif
 
 SRC_C += $(wildcard common-hal/espidf/*.c)
 
diff --git a/ports/espressif/common-hal/audiobusio/I2SOut.c b/ports/espressif/common-hal/audiobusio/I2SOut.c
index 59e8604fb7d7..54a4d243fd9a 100644
--- a/ports/espressif/common-hal/audiobusio/I2SOut.c
+++ b/ports/espressif/common-hal/audiobusio/I2SOut.c
@@ -53,7 +53,7 @@ void common_hal_audiobusio_i2sout_construct(audiobusio_i2sout_obj_t *self,
 
     i2s_std_config_t i2s_config = {
         .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(48000),
-        .slot_cfg = I2S_STD_MSB_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
+        .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
         .gpio_cfg = {
             .mclk = main_clock != NULL ? main_clock->number : I2S_GPIO_UNUSED,
             .bclk = bit_clock->number,
diff --git a/ports/espressif/common-hal/audiobusio/__init__.c b/ports/espressif/common-hal/audiobusio/__init__.c
index 9ebf325b9798..cc7768758735 100644
--- a/ports/espressif/common-hal/audiobusio/__init__.c
+++ b/ports/espressif/common-hal/audiobusio/__init__.c
@@ -35,9 +35,14 @@
 
 #include "shared-module/audiocore/__init__.h"
 
-#define CIRCUITPY_BUFFER_COUNT 3
-#define CIRCUITPY_BUFFER_SIZE 1023
-#define CIRCUITPY_OUTPUT_SLOTS 2
+// The maximum DMA buffer size (in bytes)
+#define I2S_DMA_BUFFER_MAX_SIZE     4092
+// The number of DMA buffers to allocate
+#define CIRCUITPY_BUFFER_COUNT (3)
+// The maximum DMA buffer size in frames (at stereo 16-bit)
+#define CIRCUITPY_BUFFER_SIZE (I2S_DMA_BUFFER_MAX_SIZE / 4)
+// The number of output channels is fixed at 2
+#define CIRCUITPY_OUTPUT_SLOTS (2)
 
 static void i2s_fill_buffer(i2s_t *self) {
     if (self->next_buffer_size == 0) {
diff --git a/ports/espressif/common-hal/audiomp3/__init__.c b/ports/espressif/common-hal/audiomp3/__init__.c
new file mode 100644
index 000000000000..994da3d21ad0
--- /dev/null
+++ b/ports/espressif/common-hal/audiomp3/__init__.c
@@ -0,0 +1,44 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2024 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "py/mpprint.h"
+#include "esp_heap_caps.h"
+#include "shared-module/audiomp3/__init__.h"
+#include "supervisor/port_heap.h"
+
+void *mp3_alloc(size_t sz) {
+    void *ptr = heap_caps_malloc(sz, MALLOC_CAP_8BIT);
+    if (ptr) {
+        memset(ptr, 0, sz);
+    }
+    return ptr;
+}
+
+void mp3_free(void *ptr) {
+    heap_caps_free(ptr);
+}
diff --git a/ports/espressif/common-hal/socketpool/Socket.c b/ports/espressif/common-hal/socketpool/Socket.c
index 2e10735351d4..e45f2aa6290f 100644
--- a/ports/espressif/common-hal/socketpool/Socket.c
+++ b/ports/espressif/common-hal/socketpool/Socket.c
@@ -31,8 +31,10 @@
 #include "py/mperrno.h"
 #include "py/runtime.h"
 #include "shared-bindings/socketpool/SocketPool.h"
+#if CIRCUITPY_SSL
 #include "shared-bindings/ssl/SSLSocket.h"
 #include "shared-module/ssl/SSLSocket.h"
+#endif
 #include "supervisor/port.h"
 #include "supervisor/shared/tick.h"
 #include "supervisor/workflow.h"
@@ -362,12 +364,14 @@ size_t common_hal_socketpool_socket_bind(socketpool_socket_obj_t *self,
 }
 
 void socketpool_socket_close(socketpool_socket_obj_t *self) {
+    #if CIRCUITPY_SSL
     if (self->ssl_socket) {
         ssl_sslsocket_obj_t *ssl_socket = self->ssl_socket;
         self->ssl_socket = NULL;
         common_hal_ssl_sslsocket_close(ssl_socket);
         return;
     }
+    #endif
     self->connected = false;
     int fd = self->num;
     // Ignore bogus/closed sockets
diff --git a/ports/espressif/mpconfigport.h b/ports/espressif/mpconfigport.h
index 1a97d1b6ded3..e85242dfd290 100644
--- a/ports/espressif/mpconfigport.h
+++ b/ports/espressif/mpconfigport.h
@@ -74,4 +74,11 @@
 #define CIRCUITPY_I2C_ALLOW_INTERNAL_PULL_UP (0)
 #endif
 
+// Protect the background queue with a lock because both cores may modify it.
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+extern portMUX_TYPE background_task_mutex;
+#define CALLBACK_CRITICAL_BEGIN (taskENTER_CRITICAL(&background_task_mutex))
+#define CALLBACK_CRITICAL_END (taskEXIT_CRITICAL(&background_task_mutex))
+
 #endif  // MICROPY_INCLUDED_ESPRESSIF_MPCONFIGPORT_H
diff --git a/ports/espressif/mpconfigport.mk b/ports/espressif/mpconfigport.mk
index 1b67a8db5830..445c5c69d6a4 100644
--- a/ports/espressif/mpconfigport.mk
+++ b/ports/espressif/mpconfigport.mk
@@ -22,7 +22,6 @@ CIRCUITPY_ANALOGBUFIO ?= 1
 CIRCUITPY_AUDIOBUSIO ?= 1
 CIRCUITPY_AUDIOBUSIO_PDMIN ?= 0
 CIRCUITPY_AUDIOIO ?= 0
-CIRCUITPY_AUDIOMP3 ?= 0
 CIRCUITPY_BLEIO_HCI = 0
 CIRCUITPY_CANIO ?= 1
 CIRCUITPY_COUNTIO ?= 1
@@ -143,12 +142,17 @@ endif
 ifeq ($(CIRCUITPY_ESP_FLASH_SIZE),4MB)
 CIRCUITPY_BITMAPFILTER ?= 0
 OPTIMIZATION_FLAGS ?= -Os
+# Until the 4MB C6 partition table is updated, disable mp3 on the 4MB C6 parts
+ifeq ($(IDF_TARGET),esp32c6)
+CIRCUITPY_AUDIOMP3 ?= 0
+endif
 endif
 
-# No room for dualbank on boards with 2MB flash
+# No room for dualbank or mp3 on boards with 2MB flash
 ifeq ($(CIRCUITPY_ESP_FLASH_SIZE),2MB)
 CIRCUITPY_BITMAPFILTER ?= 0
 CIRCUITPY_DUALBANK = 0
+CIRCUITPY_AUDIOMP3 = 0
 endif
 
 # Modules dependent on other modules
@@ -178,3 +182,6 @@ USB_NUM_IN_ENDPOINTS = 5
 
 # Usually lots of flash space available
 CIRCUITPY_MESSAGE_COMPRESSION_LEVEL ?= 1
+
+CIRCUITPY_AUDIOMP3 ?= 1
+CIRCUITPY_AUDIOMP3_USE_PORT_ALLOCATOR ?= 1
diff --git a/ports/espressif/supervisor/port.c b/ports/espressif/supervisor/port.c
index 7aaf1332d782..da8d10afc147 100644
--- a/ports/espressif/supervisor/port.c
+++ b/ports/espressif/supervisor/port.c
@@ -522,3 +522,5 @@ extern void app_main(void);
 void app_main(void) {
     main();
 }
+
+portMUX_TYPE background_task_mutex = portMUX_INITIALIZER_UNLOCKED;
diff --git a/py/circuitpy_defns.mk b/py/circuitpy_defns.mk
index 36af49a1a794..d01869e54426 100644
--- a/py/circuitpy_defns.mk
+++ b/py/circuitpy_defns.mk
@@ -782,7 +782,11 @@ SRC_MOD += $(addprefix lib/mp3/src/, \
 	subband.c \
 	trigtabs.c \
 )
-$(BUILD)/lib/mp3/src/buffers.o: CFLAGS += -include "py/misc.h" -D'MPDEC_ALLOCATOR(x)=m_malloc(x)' -D'MPDEC_FREE(x)=m_free(x)'
+$(BUILD)/lib/mp3/src/buffers.o: CFLAGS += -include "shared-module/audiomp3/__init__.h" -D'MPDEC_ALLOCATOR(x)=mp3_alloc(x)' -D'MPDEC_FREE(x)=mp3_free(x)' -fwrapv
+ifeq ($(CIRCUITPY_AUDIOMP3_USE_PORT_ALLOCATOR),1)
+SRC_COMMON_HAL_ALL += \
+	audiomp3/__init__.c
+endif
 endif
 
 ifeq ($(CIRCUITPY_GIFIO),1)
diff --git a/shared-bindings/audiomp3/MP3Decoder.c b/shared-bindings/audiomp3/MP3Decoder.c
index 3cb1ac4a687b..18d17e1d2eed 100644
--- a/shared-bindings/audiomp3/MP3Decoder.c
+++ b/shared-bindings/audiomp3/MP3Decoder.c
@@ -94,7 +94,9 @@ STATIC mp_obj_t audiomp3_mp3file_make_new(const mp_obj_type_t *type, size_t n_ar
         arg = mp_call_function_2(MP_OBJ_FROM_PTR(&mp_builtin_open_obj), arg, MP_ROM_QSTR(MP_QSTR_rb));
     }
 
-    audiomp3_mp3file_obj_t *self = mp_obj_malloc(audiomp3_mp3file_obj_t, &audiomp3_mp3file_type);
+    audiomp3_mp3file_obj_t *self = m_new_obj_with_finaliser(audiomp3_mp3file_obj_t);
+    self->base.type = &audiomp3_mp3file_type;
+
     if (!mp_obj_is_type(arg, &mp_type_fileio)) {
         mp_raise_TypeError(MP_ERROR_TEXT("file must be a file opened in byte mode"));
     }
@@ -260,6 +262,7 @@ STATIC const mp_rom_map_elem_t audiomp3_mp3file_locals_dict_table[] = {
     // Methods
     { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&audiomp3_mp3file_open_obj) },
     { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&audiomp3_mp3file_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&audiomp3_mp3file_deinit_obj) },
     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
     { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&audiomp3_mp3file___exit___obj) },
 
diff --git a/shared-module/audiomp3/MP3Decoder.c b/shared-module/audiomp3/MP3Decoder.c
index 51cb37d91600..08349bde70ba 100644
--- a/shared-module/audiomp3/MP3Decoder.c
+++ b/shared-module/audiomp3/MP3Decoder.c
@@ -226,7 +226,7 @@ void common_hal_audiomp3_mp3file_construct(audiomp3_mp3file_obj_t *self,
 }
 
 void common_hal_audiomp3_mp3file_set_file(audiomp3_mp3file_obj_t *self, pyb_file_obj_t *file) {
-    background_callback_begin_critical_section();
+    background_callback_prevent();
 
     self->file = file;
     f_lseek(&self->file->fp, 0);
@@ -244,7 +244,7 @@ void common_hal_audiomp3_mp3file_set_file(audiomp3_mp3file_obj_t *self, pyb_file
     memset(self->buffers[1], 0, MAX_BUFFER_LEN);
     MP3FrameInfo fi;
     bool result = mp3file_get_next_frame_info(self, &fi);
-    background_callback_end_critical_section();
+    background_callback_allow();
     if (!result) {
         mp_raise_msg(&mp_type_RuntimeError,
             MP_ERROR_TEXT("Failed to parse MP3 file"));
@@ -296,7 +296,7 @@ void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t *self,
     }
     // We don't reset the buffer index in case we're looping and we have an odd number of buffer
     // loads
-    background_callback_begin_critical_section();
+    background_callback_prevent();
     f_lseek(&self->file->fp, 0);
     self->inbuf_offset = self->inbuf_length;
     self->eof = 0;
@@ -305,7 +305,7 @@ void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t *self,
     mp3file_update_inbuf_half(self);
     mp3file_skip_id3v2(self);
     mp3file_find_sync_word(self);
-    background_callback_end_critical_section();
+    background_callback_allow();
 }
 
 audioio_get_buffer_result_t audiomp3_mp3file_get_buffer(audiomp3_mp3file_obj_t *self,
diff --git a/shared-module/audiomp3/__init__.c b/shared-module/audiomp3/__init__.c
index e69de29bb2d1..5141f4ab05b4 100644
--- a/shared-module/audiomp3/__init__.c
+++ b/shared-module/audiomp3/__init__.c
@@ -0,0 +1,38 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2024 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include "py/mpconfig.h"
+#include "py/misc.h"
+#include "shared-module/audiomp3/__init__.h"
+
+MP_WEAK void *mp3_alloc(size_t sz) {
+    return m_malloc_maybe(sz);
+}
+
+MP_WEAK void mp3_free(void *ptr) {
+    m_free(ptr);
+}
diff --git a/shared-module/audiomp3/__init__.h b/shared-module/audiomp3/__init__.h
index e7b1f3aab534..6d8a8514ed24 100644
--- a/shared-module/audiomp3/__init__.h
+++ b/shared-module/audiomp3/__init__.h
@@ -24,7 +24,9 @@
  * THE SOFTWARE.
  */
 
-#ifndef MICROPY_INCLUDED_SHARED_MODULE_AUDIOMP3__INIT__H
-#define MICROPY_INCLUDED_SHARED_MODULE_AUDIOMP3__INIT__H
+#pragma once
 
-#endif  // MICROPY_INCLUDED_SHARED_MODULE_AUDIOMP3__INIT__H
+#include <stdlib.h>
+
+extern void *mp3_alloc(size_t sz);
+extern void mp3_free(void *ptr);
diff --git a/supervisor/background_callback.h b/supervisor/background_callback.h
index 36b0017f0cae..4be62c081eb2 100644
--- a/supervisor/background_callback.h
+++ b/supervisor/background_callback.h
@@ -89,8 +89,8 @@ void background_callback_reset(void);
  * bracket the section of code where this is the case.  These calls nest, and
  * begins must be balanced with ends.
  */
-void background_callback_begin_critical_section(void);
-void background_callback_end_critical_section(void);
+void background_callback_prevent(void);
+void background_callback_allow(void);
 
 /*
  * Background callbacks may stop objects from being collected
diff --git a/supervisor/shared/background_callback.c b/supervisor/shared/background_callback.c
index 776435ac5570..a8c0f071faf9 100644
--- a/supervisor/shared/background_callback.c
+++ b/supervisor/shared/background_callback.c
@@ -76,18 +76,19 @@ inline bool background_callback_pending(void) {
     return callback_head != NULL;
 }
 
-static bool in_background_callback;
+static int background_prevention_count;
+
 void PLACE_IN_ITCM(background_callback_run_all)() {
     port_background_task();
     if (!background_callback_pending()) {
         return;
     }
     CALLBACK_CRITICAL_BEGIN;
-    if (in_background_callback) {
+    if (background_prevention_count) {
         CALLBACK_CRITICAL_END;
         return;
     }
-    in_background_callback = true;
+    ++background_prevention_count;
     background_callback_t *cb = (background_callback_t *)callback_head;
     callback_head = NULL;
     callback_tail = NULL;
@@ -104,15 +105,19 @@ void PLACE_IN_ITCM(background_callback_run_all)() {
         CALLBACK_CRITICAL_BEGIN;
         cb = next;
     }
-    in_background_callback = false;
+    --background_prevention_count;
     CALLBACK_CRITICAL_END;
 }
 
-void background_callback_begin_critical_section() {
+void background_callback_prevent() {
     CALLBACK_CRITICAL_BEGIN;
+    ++background_prevention_count;
+    CALLBACK_CRITICAL_END;
 }
 
-void background_callback_end_critical_section() {
+void background_callback_allow() {
+    CALLBACK_CRITICAL_BEGIN;
+    --background_prevention_count;
     CALLBACK_CRITICAL_END;
 }
 
@@ -146,7 +151,7 @@ void background_callback_reset() {
     }
     callback_head = new_head;
     callback_tail = new_tail;
-    in_background_callback = false;
+    background_prevention_count = 0;
     CALLBACK_CRITICAL_END;
 }