From 0dce96ca21bcde277a09ecfefa2b798143b57968 Mon Sep 17 00:00:00 2001
From: arighi <arighi@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Mon, 14 Mar 2011 14:40:07 +0000
Subject: [PATCH] STM32: flash: make flash_wait() a voluntary preemption point
A process that writes large chunks of data to the embedded flash can
monopolize the CPU for a very long time if the flash is fast enough to
write data words.
This is bad from the real-time perspective, so make flash_wait() a
voluntary preemption point, also in the case when the flash is fast
enough and never goes in busy state.
git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4771 38d2e660-2303-0410-9eaa-f027e97ec537
---
bertos/cpu/cortex-m3/drv/flash_stm32.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/bertos/cpu/cortex-m3/drv/flash_stm32.c b/bertos/cpu/cortex-m3/drv/flash_stm32.c
index 816cdd58..d92e9142 100644
--- a/bertos/cpu/cortex-m3/drv/flash_stm32.c
+++ b/bertos/cpu/cortex-m3/drv/flash_stm32.c
@@ -67,6 +67,7 @@ static bool flash_wait(struct KBlock *blk)
ticks_t start = timer_clock();
while (true)
{
+ cpu_relax();
if (!(EMB_FLASH->SR & FLASH_FLAG_BSY))
break;
@@ -90,8 +91,6 @@ static bool flash_wait(struct KBlock *blk)
LOG_ERR("Timeout..\n");
return false;
}
-
- cpu_relax();
}
return true;
--
2.34.1