From mboxrd@z Thu Jan 1 00:00:00 1970 From: ladis@linux-mips.org (Ladislav Michl) Date: Wed, 17 Jan 2018 22:47:14 +0100 Subject: [PATCH 1/3] clocksource: timer-dm: Check prescaler value In-Reply-To: <20180117214629.GA11952@lenoch> References: <20180117214629.GA11952@lenoch> Message-ID: <20180117214714.GB11952@lenoch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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; }