Messages in this thread | | | Date | Mon, 22 Jan 2018 10:59:50 +0100 | From | Ladislav Michl <> | Subject | Re: [PATCH 1/3] clocksource: timer-dm: Check prescaler value |
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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@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) > You are checking the prescaller here to be in [0, 7] interval.
You mean [-1, 7] I suppose.
> > 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
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