From ef47a67cf42246bbcf3c81e5f89e0e25db9dff74 Mon Sep 17 00:00:00 2001
From: Peter Hinch <peter@hinch.me.uk>
Date: Mon, 13 Jun 2016 08:54:57 +0100
Subject: [PATCH] stmhal/dac: Fix DAC (re-)initialisation by resetting DMA.

Fixes issue #2176.
---
 stmhal/dac.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/stmhal/dac.c b/stmhal/dac.c
index 7493bb59ab..a9b1b9eca7 100644
--- a/stmhal/dac.c
+++ b/stmhal/dac.c
@@ -171,6 +171,14 @@ STATIC mp_obj_t pyb_dac_init_helper(pyb_dac_obj_t *self, mp_uint_t n_args, const
     #endif
 
     // stop anything already going on
+    __DMA1_CLK_ENABLE();
+    DMA_HandleTypeDef DMA_Handle;
+    /* Get currently configured dma */
+    dma_init_handle(&DMA_Handle, self->tx_dma_descr, (void*)NULL);
+    // Need to deinit DMA first
+    DMA_Handle.State = HAL_DMA_STATE_READY;
+    HAL_DMA_DeInit(&DMA_Handle);
+
     HAL_DAC_Stop(&DAC_Handle, self->dac_channel);
     if ((self->dac_channel == DAC_CHANNEL_1 && DAC_Handle.DMA_Handle1 != NULL)
             || (self->dac_channel == DAC_CHANNEL_2 && DAC_Handle.DMA_Handle2 != NULL)) {