Re: [RFC PATCH 02/10] clockevents/drivers: add MPS2 Timer driver
From: Vladimir Murzin <hidden>
Date: 2015-11-25 14:51:14
Also in:
linux-api, linux-arm-kernel, linux-serial, lkml
From: Vladimir Murzin <hidden>
Date: 2015-11-25 14:51:14
Also in:
linux-api, linux-arm-kernel, linux-serial, lkml
Hi Daniel, Thanks for you review, I agree on all concerns raised and address them in the next version. Just some points to confirm below (I left only relevant parts).
quoted
+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) + return IRQ_NONE;Why that could happen ? Add a comment.
Sort of defensive programming, I never seen it happens, but just in case
of spurious interrupts... Do you prefer to get rid of this check or
/* spurious interrupt? */
if (!status)
return IRQ_NONE;
would be fine to you?
quoted
+} + +static void __init mps2_timer_init(struct device_node *np) +{ + static int clksrc; + + if (!clksrc && !mps2_clocksource_init(np)) + clksrc = 1; + else + mps2_clockevents_init(np);That assumes the clocksource is defined before the clockevents in the DT. If it is not the case, the mps2_clocksource_init will fail (and spit errors) and mps2_clockevents_init() won't be called.
Does following (stolen from efm32) look better to you?
static void __init mps2_timer_init(struct device_node *np)
{
static int has_clocksource, has_clockevent;
int ret;
if (!has_clocksource) {
ret = mps2_clocksource_init(np);
if (!ret) {
has_clocksource = 1;
return;
}
}
if (!has_clockevent) {
ret = mps2_clockevent_init(np);
if (!ret) {
has_clockevent = 1;
return;
}
}
}
Thanks
Vladimir
quoted
+} + +CLOCKSOURCE_OF_DECLARE(mps2_timer, "arm,mps2-timer", mps2_timer_init);