[U-Boot] PATCH mtd CFI flash: timeout calculation underflow if imprecise 1kHz timer: fix

Renato Andreola renato.andreola at imagos.it
Thu Aug 6 11:49:32 CEST 2009


 From be54cb97ca26bcbbc1a908d1f2a5447b6639dc59 Mon Sep 17 00:00:00 2001
From: Renato Andreola <renato.andreola at imagos.it>
Date: Thu, 6 Aug 2009 11:40:52 +0200
Subject: [PATCH] drivers/mtd/cfi_flash: precision and underflow problem 
in tout calculation

With old configuration it could happen tout=0 if CONFIG_SYS_HZ<1000
solved using an unsigned long long

Signed-off-by: Renato Andreola renato.andreola at imagos.it
---
  drivers/mtd/cfi_flash.c |    6 ++++--
  1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 81ac5d3..6bcd102 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -659,8 +659,10 @@ static int flash_status_check (flash_info_t * info, 
flash_sect_t sector,
  {
  	ulong start;

-#if CONFIG_SYS_HZ != 1000
-	tout *= CONFIG_SYS_HZ/1000;
+#if CONFIG_SYS_HZ != 1000	
+	unsigned long long ull;
+	ull = tout*CONFIG_SYS_HZ + CONFIG_SYS_HZ/2;
+	tout = ull/1000; /* Compute: tout *= CONFIG_SYS_HZ/1000; */
  #endif

  	/* Wait for command completion */
-- 
1.5.5






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