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 --- drivers/mtd/stm32_flash.c | 4 ++++ 1 file changed, 4 insertions(+)

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 @@ int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt) /* 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) ; }