From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 14 Dec 2015 14:36:18 +0100 Subject: [PATCH v1 02/10] clockevents/drivers: add MPS2 Timer driver In-Reply-To: <1449048790-25859-3-git-send-email-vladimir.murzin@arm.com> References: <1449048790-25859-1-git-send-email-vladimir.murzin@arm.com> <1449048790-25859-3-git-send-email-vladimir.murzin@arm.com> Message-ID: <566EC5D2.9050005@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/02/2015 10:33 AM, Vladimir Murzin wrote: > MPS2 platform has simple 32 bits general purpose countdown timers. > > The driver uses the first detected timer as a clocksource and the rest > of the timers as a clockevent > > Signed-off-by: Vladimir Murzin > --- [ ... ] > +static void clockevent_mps2_writel(u32 val, struct clock_event_device *c, u32 offset) > +{ > + writel(val, to_mps2_clkevt(c)->reg + offset); > +} Is it possible to use writel_relaxed here ? [ ... ] > +static int mps2_timer_set_periodic(struct clock_event_device *ce) > +{ > + u32 clock_count_per_tick = to_mps2_clkevt(ce)->clock_count_per_tick; > + > + clockevent_mps2_writel(clock_count_per_tick, ce, TIMER_RELOAD); > + clockevent_mps2_writel(clock_count_per_tick, ce, TIMER_VALUE); > + clockevent_mps2_writel(TIMER_CTRL_IE | TIMER_CTRL_ENABLE, ce, TIMER_CTRL); > + > + return 0; > +} > + > +static irqreturn_t mps2_timer_interrupt(int irq, void *dev_id) > +{ > + struct clockevent_mps2 *ce = dev_id; > + u32 status = readl(ce->reg + TIMER_INT); > + > + if (!status) { > + pr_warn("spuirous interrupt\n"); typo: 'spurious' [ ... ] > + ce = kzalloc(sizeof(struct clockevent_mps2), GFP_KERNEL); > + if (!ce) { > + ret = -ENOMEM; > + pr_err("failed to allocate clockevent: %d\n", ret); There is already a stack trace in the kernel when an allocation fails. With the above fixed: Acked-by: Daniel Lezcano -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog