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

Renato Andreola renato.andreola at imagos.it
Fri Apr 10 14:28:59 CEST 2009


 From 6cc63851e5e4c16012d9afad70cedb41b7340de7 Mon Sep 17 00:00:00 2001
From: Renato Andreola <renato.andreola at imagos.it>
Date: Fri, 10 Apr 2009 12:52:55 +0200
Subject: 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
---
  drivers/mtd/cfi_flash.c |    4 +++-
  1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 175d82a..0aa42a2 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -660,7 +660,9 @@ 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;
+	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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