On 11/25/2015 03:51 PM, Vladimir Murzin wrote:

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

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?

Yes, that would be fine, but if it does never happen, we don't really 
need this check. If you prefer to make sure there isn't a spurious 
interrupt and considering it shouldn't happen, a pr_info trace may help 
to spot this misbehavior.

quoted

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;
		}
	}
}

Yes.

I don't like to have a "CLOCKSOURCE_OF_DECLARE" to initialize a 
clockevent but I can't blame you, this is what is done in the other drivers.

quoted

quoted

+}
+
+CLOCKSOURCE_OF_DECLARE(mps2_timer, "arm,mps2-timer", mps2_timer_init);

-- 
  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog