From 9082517a85930740f59966fcf13293c38792afe8 Mon Sep 17 00:00:00 2001 From: Vikas Manocha Date: Mon, 4 Apr 2016 16:49:02 -0700 Subject: [PATCH] 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 --- 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) ; } -- 2.7.4