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

[Renato Andreola]

 From 21d84ab72266f118794233176bd356d8b1cfdf35 Mon Sep 17 00:00:00 2001
From: Renato Andreola <renato.andreola at imagos.it>
Date: Fri, 21 Aug 2009 18:05:51 +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.

Signed-off-by: Alessandro Rubini <rubini at gnudd.com> Renato Andreola <renato.andreola at imagos.it>
---
  drivers/mtd/cfi_flash.c |    8 +++++---
  1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 81ac5d3..0d8fc54 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -660,9 +660,11 @@ 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;
-#endif
-
+	if ((ulong)CONFIG_SYS_HZ > 100000)
+		tout *= (ulong)CONFIG_SYS_HZ/1000;  /* for a big HZ, avoid overflow */
+	else
+		tout = DIV_ROUND_UP(tout*(ulong)CONFIG_SYS_HZ, 1000);
+#endif	
  	/* Wait for command completion */
  	start = get_timer (0);
  	while (flash_is_busy (info, sector)) {
-- 
1.5.5