stm32h7: Fix race condition in ADC interrupt handling

arch/arm/src/stm32h7/stm32_adc.c

@@ -1253,6 +1253,8 @@ static void adc_enable(struct stm32_dev_s *priv)
   /* Wait for hardware to be ready for conversions */
 
   while (!(adc_getreg(priv, STM32_ADC_ISR_OFFSET) & ADC_INT_ADRDY));
+
+  adc_modifyreg(priv, STM32_ADC_ISR_OFFSET, 0, ADC_INT_ADRDY);
 }
 
 /****************************************************************************
@@ -2008,6 +2010,13 @@ static int adc_interrupt(struct adc_dev_s *dev, uint32_t adcisr)
       /* Stop ADC conversions to avoid continuous interrupts */
 
       adc_startconv(priv, false);
+
+      /* Clear the interrupt. This register only accepts write 1's so its
+       * safe to only set the 1 bit without regard for the rest of the
+       * register
+       */
+
+      adc_putreg(priv, STM32_ADC_ISR_OFFSET, ADC_INT_AWD1);
     }
 
   /* OVR: Overrun */
@@ -2037,6 +2046,11 @@ static int adc_interrupt(struct adc_dev_s *dev, uint32_t adcisr)
           priv->cb->au_reset(dev);
         }
 
+      /* Clear the interrupt. This register only accepts write 1's so its
+       * safe to only set the 1 bit without regard for the rest of the
+       * register
+       */
+
       adc_putreg(priv, STM32_ADC_ISR_OFFSET, ADC_INT_OVR);
     }
 
@@ -2091,6 +2105,10 @@ static int adc_interrupt(struct adc_dev_s *dev, uint32_t adcisr)
             }
         }
       while ((adc_getreg(priv, STM32_ADC_ISR_OFFSET) & ADC_INT_EOC) != 0);
+
+      /* We dont't add EOC to the bits to clear. It will cause a race
+       * condition.  EOC should only be cleared by reading the ADC_DR
+       */
     }
 
   return OK;
@@ -2120,10 +2138,6 @@ static int adc12_interrupt(int irq, void *context, void *arg)
   if (pending != 0)
     {
       adc_interrupt(&g_adcdev1, regval);
-
-      /* Clear interrupts */
-
-      putreg32(regval, STM32_ADC1_ISR);
     }
 #endif
 
@@ -2133,10 +2147,6 @@ static int adc12_interrupt(int irq, void *context, void *arg)
   if (pending != 0)
     {
       adc_interrupt(&g_adcdev2, regval);
-
-      /* Clear interrupts */
-
-      putreg32(regval, STM32_ADC2_ISR);
     }
 #endif
 
@@ -2167,10 +2177,6 @@ static int adc3_interrupt(int irq, void *context, void *arg)
   if (pending != 0)
     {
       adc_interrupt(&g_adcdev3, regval);
-
-      /* Clear interrupts */
-
-      putreg32(regval, STM32_ADC3_ISR);
     }
 
   return OK;