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authorHugo Villeneuve <hugo.villeneuve@lyrtech.com>2008-07-11 10:24:15 -0400
committerWolfgang Denk <wd@denx.de>2008-07-13 15:13:31 +0200
commitef130d3093bdf88f01cf3e000fe5df249ebf2b1a (patch)
treeb04b2b5e0c0819dcf22d630d2fe9a8b7be475e76
parent6b760189d77f001684e3160b355c185ca3804961 (diff)
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Fix integer overflow warning in calc_divisor()
which happened when rounding the serial port clock divisor Signed-off-by: Hugo Villeneuve <hugo.villeneuve@lyrtech.com>
-rw-r--r--drivers/serial/serial.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 182ca2d..4ccaee2 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -124,6 +124,8 @@ static NS16550_t serial_ports[4] = {
static int calc_divisor (NS16550_t port)
{
+ uint32_t clk_divisor;
+
#ifdef CONFIG_OMAP1510
/* If can't cleanly clock 115200 set div to 1 */
if ((CFG_NS16550_CLK == 12000000) && (gd->baudrate == 115200)) {
@@ -147,10 +149,15 @@ static int calc_divisor (NS16550_t port)
/* Compute divisor value. Normally, we should simply return:
* CFG_NS16550_CLK) / MODE_X_DIV / gd->baudrate
- * but we need to round that value by adding 0.5 or 8/16.
+ * but we need to round that value by adding 0.5 (2/4).
* Rounding is especially important at high baud rates.
*/
- return (((16 * CFG_NS16550_CLK) / MODE_X_DIV / gd->baudrate) + 8) / 16;
+ clk_divisor = (((4 * CFG_NS16550_CLK) /
+ (MODE_X_DIV * gd->baudrate)) + 2) / 4;
+
+ debug("NS16550 clock divisor = %d\n", clk_divisor);
+
+ return clk_divisor;
}
#if !defined(CONFIG_SERIAL_MULTI)