diff --git a/platforms/pico/drivers/serial.c b/platforms/pico/drivers/serial.c
index 15e71c5215..116dc6f5dc 100644
--- a/platforms/pico/drivers/serial.c
+++ b/platforms/pico/drivers/serial.c
@@ -68,7 +68,7 @@ inline static bool serial_read_pin(void) { return readPin(SOFT_SERIAL_PIN); }
 inline static void serial_low(void) { writePinLow(SOFT_SERIAL_PIN); }
 inline static void serial_high(void) { writePinHigh(SOFT_SERIAL_PIN); }
 
-void interrupt_handler(uint gpio, uint32_t events);
+static void interrupt_handler(uint gpio, uint32_t events);
 
 static PIO  pio = pio0;
 static uint sm_tx, sm_rx;
@@ -144,7 +144,7 @@ void soft_serial_target_init(void) {
 }
 
 // Used by the master to synchronize timing with the slave.
-static int __attribute__((noinline)) sync_recv(void) {
+static int __no_inline_not_in_flash_func(sync_recv)(void) {
     serial_input();
 
     volatile uint64_t timeout = time_us_64() + 10000;
@@ -180,7 +180,7 @@ static int __attribute__((noinline)) sync_recv(void) {
 }
 
 // Used by the slave to send a synchronization signal to the master.
-static void __attribute__((noinline)) sync_send(void) {
+static void __no_inline_not_in_flash_func(sync_send)(void) {
     serial_output();
 
     serial_low();
@@ -220,7 +220,7 @@ static void serial_wait_send_complete(void) {
 }
 
 // interrupt handle to be used by the slave device
-void interrupt_handler(uint gpio, uint32_t events) {
+static void __no_inline_not_in_flash_func(interrupt_handler)(uint gpio, uint32_t events) {
     if (gpio != SOFT_SERIAL_PIN || events != GPIO_IRQ_EDGE_FALL) {
         return;
     }
@@ -339,7 +339,7 @@ void interrupt_handler(uint gpio, uint32_t events) {
 //    TRANSACTION_NO_RESPONSE
 //    TRANSACTION_DATA_ERROR
 // this code is very time dependent, so we need to disable interrupts
-int soft_serial_transaction(int sstd_index) {
+int __no_inline_not_in_flash_func(soft_serial_transaction)(int sstd_index) {
     if (sstd_index > NUM_TOTAL_TRANSACTIONS) return TRANSACTION_TYPE_ERROR;
     split_transaction_desc_t *trans = &split_transaction_table[sstd_index];
     if (!trans->status) return TRANSACTION_TYPE_ERROR;  // not registered
diff --git a/platforms/pico/drivers/ws2812.c b/platforms/pico/drivers/ws2812.c
index 3eea6092ae..91eb8eadc5 100644
--- a/platforms/pico/drivers/ws2812.c
+++ b/platforms/pico/drivers/ws2812.c
@@ -1,16 +1,21 @@
+// Copyright 2022 sekigon-gonnoc
+// SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <stdio.h>
 
 #include "ws2812.h"
 #include "ws2812.pio.h"
 
+#include "atomic_util.h"
 #include "pio_manager.h"
 #include "boards/pico_boards.h"
 
 #include "pico/stdlib.h"
+#include "hardware/dma.h"
 
-static PIO pio = pio0;
-static int sm  = 0;
+static PIO pio    = pio0;
+static int sm     = 0;
+static int dma_ch = 1;
 
 static int ws2812_init(void) {
     sm = pio_manager_get_empty_sm(pio);
@@ -27,6 +32,15 @@ static int ws2812_init(void) {
 
     ws2812_program_init(pio, sm, offset, RGB_DI_PIN, 800000, false);
 
+    dma_channel_config conf = dma_channel_get_default_config(dma_ch);
+
+    channel_config_set_read_increment(&conf, true);
+    channel_config_set_write_increment(&conf, false);
+    channel_config_set_transfer_data_size(&conf, DMA_SIZE_32);
+    channel_config_set_dreq(&conf, pio_get_dreq(pio, sm, true));
+
+    dma_channel_set_config(dma_ch, &conf, false);
+    dma_channel_set_write_addr(dma_ch, &pio->txf[sm], false);
     return 0;
 }
 
@@ -40,12 +54,13 @@ void ws2812_setleds(LED_TYPE *ledarray, uint16_t number_of_leds) {
         }
     }
 
-    printf("led %d %d %d\n", ledarray[0].r, ledarray[0].g, ledarray[0].b);
-
+    uint32_t leddata[RGBLED_NUM];
     for (int i = 0; i < number_of_leds; i++) {
-        pio_sm_put_blocking(pio, sm,
-                            (((uint32_t)ledarray[i].r) << 16) |
-                                (((uint32_t)ledarray[i].g) << 24) |
-                                ((uint32_t)ledarray[i].b << 8));
+        leddata[i] = (((uint32_t)ledarray[i].g) << 24) |
+                     (((uint32_t)ledarray[i].r) << 16) |
+                     ((uint32_t)ledarray[i].b << 8);
     }
+
+    dma_channel_transfer_from_buffer_now(dma_ch, leddata, number_of_leds);
+    dma_channel_wait_for_finish_blocking(dma_ch);
 }