stm32: stm32_flash: add memory barrier during flash write
After writing data to flash space, next instruction is checking if flash
controller is busy writing to the flash memory. Memory barrier is required here
to avoid transaction re-ordering for data write and busy status check.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/drivers/mtd/stm32_flash.c b/drivers/mtd/stm32_flash.c
index 71f4854..e16b6cd 100644
--- a/drivers/mtd/stm32_flash.c
+++ b/drivers/mtd/stm32_flash.c
@@ -137,6 +137,10 @@
/* To make things simple use byte writes only */
for (i = 0; i < cnt; i++) {
*(uchar *)(addr + i) = src[i];
+ /* avoid re-ordering flash data write and busy status
+ * check as flash memory space attributes are generally Normal
+ */
+ mb();
while (readl(&STM32_FLASH->sr) & STM32_FLASH_SR_BSY)
;
}