From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ladislav Michl Subject: Re: [PATCH v6 10/10] clocksource: timer-dm: Check prescaler value Date: Thu, 4 Jan 2018 23:47:13 +0100 Message-ID: <20180104224713.GA11557@lenoch> References: <1514887799-24605-1-git-send-email-j-keerthy@ti.com> <1514887799-24605-11-git-send-email-j-keerthy@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1514887799-24605-11-git-send-email-j-keerthy@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Keerthy Cc: daniel.lezcano@linaro.org, tony@atomide.com, aaro.koskinen@iki.fi, thierry.reding@gmail.com, grygorii.strashko@ti.com, linux-omap@vger.kernel.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, sebastian.reichel@collabora.co.uk, linux-kernel@vger.kernel.org, t-kristo@ti.com List-Id: linux-omap@vger.kernel.org On Tue, Jan 02, 2018 at 03:39:59PM +0530, Keerthy wrote: > From: Ladislav Michl > > Invalid prescaler value is silently ignored. Fix that > by returning -EINVAL in such case. As invalid value > disabled use of the prescaler, use -1 explicitely for > that purpose. > > Signed-off-by: Ladislav Michl > --- > drivers/clocksource/timer-dm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/clocksource/timer-dm.c b/drivers/clocksource/timer-dm.c > index 60db173..01a9cb0 100644 > --- a/drivers/clocksource/timer-dm.c > +++ b/drivers/clocksource/timer-dm.c > @@ -672,6 +672,9 @@ int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler) > if (prescaler >= 0x00 && prescaler <= 0x07) { > l |= OMAP_TIMER_CTRL_PRE; > l |= prescaler << 2; > + } else { > + if (prescaler != -1) > + return -EINVAL; Argh... This is actually wrong, as it leaves timer enabled. I suggest simply dropping this patch and I'll rethink whole approach a bit later (and better). > } > omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l); > Sorry for the noise, ladis