Fix DMA buffer release in ADC/DAC.

* Release buffers before deallocing pool.

Author: iabdalkader

src/AdvancedADC.cpp

@@ -60,19 +60,19 @@ static void dac_descr_deinit(adc_descr_t *descr, bool dealloc_pool) {
         HAL_TIM_Base_Stop(&descr->tim);
         HAL_ADC_Stop_DMA(&descr->adc);
 
-        if (dealloc_pool) {
-            if (descr->pool) {
-                delete descr->pool;
-            }
-            descr->pool = nullptr;
-        }
-
         for (size_t i=0; i<AN_ARRAY_SIZE(descr->dmabuf); i++) {
             if (descr->dmabuf[i]) {
                 descr->dmabuf[i]->release();
                 descr->dmabuf[i] = nullptr;
             }
         }
+
+        if (dealloc_pool) {
+            if (descr->pool) {
+                delete descr->pool;
+            }
+            descr->pool = nullptr;
+        }
     }
 }
 

src/AdvancedDAC.cpp

@@ -58,19 +58,20 @@ static void dac_descr_deinit(dac_descr_t *descr, bool dealloc_pool) {
         HAL_TIM_Base_Stop(&descr->tim);
         HAL_DAC_Stop_DMA(descr->dac, descr->channel);
 
+        for (size_t i=0; i<AN_ARRAY_SIZE(descr->dmabuf); i++) {
+            if (descr->dmabuf[i]) {
+                descr->dmabuf[i]->release();
+                descr->dmabuf[i] = nullptr;
+            }
+        }
+
         if (dealloc_pool) {
             if (descr->pool) {
                 delete descr->pool;
             }
             descr->pool = nullptr;
         }
 
-        for (size_t i=0; i<AN_ARRAY_SIZE(descr->dmabuf); i++) {
-            if (descr->dmabuf[i]) {
-                descr->dmabuf[i]->release();
-                descr->dmabuf[i] = nullptr;
-            }
-        }
     }
 }
 
@@ -158,7 +159,7 @@ int AdvancedDAC::begin(uint32_t resolution, uint32_t frequency, size_t n_samples
 
 int AdvancedDAC::stop()
 {
-    dac_descr_deinit(descr, false);
+    dac_descr_deinit(descr, true);
     return 1;
 }