On 22.01.2018 11:59, Ladislav Michl wrote: > On Mon, Jan 22, 2018 at 11:00:15AM +0200, Claudiu Beznea wrote: >> >> >> On 17.01.2018 23:47, Ladislav Michl wrote: >>> 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@xxxxxxxxxxxxxx> >>> --- >>> 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) >> You are checking the prescaller here to be in [0, 7] interval. > > You mean [-1, 7] I suppose. Right, [-1, 7], my bad. Ok, So you use -1 to disable the prescaler. > >>> 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) { >> Is this check still necessary? > > Yes, as we need also some way to disable prescaler, see commit message. > >>> l |= OMAP_TIMER_CTRL_PRE; >>> l |= prescaler << 2; >>> } > > Best regards, > ladis > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html