clocksource: timer-ti-dm: Check prescaler value
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 <ladis@linux-mips.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
index 6abe5ab..4cce6b2 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -663,13 +663,13 @@ static int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer,
{
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;
}