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

Renato Andreola
2009-08-24T08:32:17Z

From 21d84ab72266f118794233176bd356d8b1cfdf35 Mon Sep 17 00:00:00 2001
From: Renato Andreola <renato.andreola@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@gnudd.com> Renato Andreola <renato.andreola@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