On 25/11/15 15:10, Daniel Lezcano wrote:

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

quoted

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).

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+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.

Good, I'll put pr_warn("spurious interrupt\n") then.

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+}
+
+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.

Thanks for your time!

Vladimir

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

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