nuttx-patches: Add workaround for flash data cache corruption on read-while-write

8 years ago · 03e3877535
1 changed files with 81 additions and 0 deletions
--- a/nuttx-patches/workarround_for_flash_data_cache_corruption.patch
+++ b/nuttx-patches/workarround_for_flash_data_cache_corruption.patch
@ -0,0 +1,81 @@
				@@ -0,0 +1,81 @@
+diff --git NuttX/nuttx/arch/arm/src/stm32/Kconfig NuttX/nuttx/arch/arm/src/stm32/Kconfig
+index b6c0458649..d9fb0aeaa2 100644
+--- NuttX/nuttx/arch/arm/src/stm32/Kconfig
+++ NuttX/nuttx/arch/arm/src/stm32/Kconfig
+@@ -2514,6 +2514,12 @@ config STM32_FLASH_PREFETCH
+ 	on F1 parts).  Some early revisions of F4 parts do not support FLASH pre-fetch
+ 	properly and enabling this option may interfere with ADC accuracy.
+ 
+config STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW
+    bool "Enable the workaround to fix flash data cache corruption when reading from one flash bank while writing on other flash bank"
+    default n
+    ---help---
+    See your STM32 errata to check if your STM32 is affected by this problem.
+
+ choice
+ 	prompt "JTAG Configuration"
+ 	default STM32_JTAG_DISABLE
+diff --git NuttX/nuttx/arch/arm/src/stm32/stm32_flash.c NuttX/nuttx/arch/arm/src/stm32/stm32_flash.c
+index 73f1419506..fd0b05d624 100644
+--- NuttX/nuttx/arch/arm/src/stm32/stm32_flash.c
+++ NuttX/nuttx/arch/arm/src/stm32/stm32_flash.c
+@@ -294,6 +294,37 @@ ssize_t up_progmem_ispageerased(size_t page)
+   return bwritten;
+ }
+ 
+#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
+static void data_cache_disable(void)
+{
+  uint32_t value = getreg32(STM32_FLASH_ACR);
+
+  if (value & FLASH_ACR_DCEN)
+    {
+      value &= ~FLASH_ACR_DCEN;
+      putreg32(value, STM32_FLASH_ACR);
+    }
+}
+
+static void data_cache_enable(void)
+{
+  uint32_t value = getreg32(STM32_FLASH_ACR);
+  if (value & FLASH_ACR_DCEN)
+    {
+      return;
+    }
+
+  /* reset data cache */
+  value |= FLASH_ACR_DCRST;
+  putreg32(value, STM32_FLASH_ACR);
+
+  /* enable data cache */
+  value = getreg32(STM32_FLASH_ACR);
+  value |= FLASH_ACR_DCEN;
+  putreg32(value, STM32_FLASH_ACR);
+}
+#endif
+
+ ssize_t up_progmem_write(size_t addr, const void *buf, size_t count)
+ {
+   uint16_t *hword = (uint16_t *)buf;
+@@ -327,6 +358,10 @@ ssize_t up_progmem_write(size_t addr, const void *buf, size_t count)
+ 
+   stm32_flash_unlock();
+ 
+#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
+  data_cache_disable();
+#endif
+
+   modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_PG);
+ 
+ #if defined(CONFIG_STM32_STM32F40XX)
+@@ -358,6 +393,10 @@ ssize_t up_progmem_write(size_t addr, const void *buf, size_t count)
+     }
+ 
+   modifyreg32(STM32_FLASH_CR, FLASH_CR_PG, 0);
+
+#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
+  data_cache_enable();
+#endif
+   return written;
+ }
+