[PATCH 1/3] clocksource: timer-dm: Check prescaler value

[Ladislav Michl]

Invalid value silently disables use of the prescaler.
Use -1 explicitely for that purpose and error out on
invalid value.

Signed-off-by: Ladislav Michl <la...@linux-mips.org>
---
 drivers/clocksource/timer-dm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/timer-dm.c b/drivers/clocksource/timer-dm.c
index 60db1734ea3b..324ec93d3dd2 100644
--- a/drivers/clocksource/timer-dm.c
+++ b/drivers/clocksource/timer-dm.c
@@ -663,13 +663,13 @@ int omap_dm_timer_set_prescaler(struct omap_dm_timer 
*timer, int prescaler)
 {
        u32 l;
 
-       if (unlikely(!timer))
+       if (unlikely(!timer) || prescaler < -1 || prescaler > 7)
                return -EINVAL;
 
        omap_dm_timer_enable(timer);
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        l &= ~(OMAP_TIMER_CTRL_PRE | (0x07 << 2));
-       if (prescaler >= 0x00 && prescaler <= 0x07) {
+       if (prescaler >= 0) {
                l |= OMAP_TIMER_CTRL_PRE;
                l |= prescaler << 2;
        }