Re: [PATCH v4] ARM: clocksource: add support for MOXA ART SoCs

From: Thomas Gleixner
Date: Mon Jul 01 2013 - 13:55:22 EST


On Mon, 1 Jul 2013, Jonas Jensen wrote:
> +static int moxart_clkevt_next_event(unsigned long cycles,
> + struct clock_event_device *unused)
> +{
> + u32 u;
> +
> + u = readl(base + TIMER_CR) & ~TIMEREG_CR_1_ENABLE;

You should cache that value and avoid another readout below. You could
even cache it in general so you avoid all readouts.

> + writel(u, base + TIMER_CR);
> + u = readl(base + TIMER1_BASE + REG_COUNT) - cycles;
> + writel(u, base + TIMER1_BASE + REG_MATCH1);
> + u = readl(base + TIMER_CR) | TIMEREG_CR_1_ENABLE;
> + writel(u, base + TIMER_CR);
> + return 0;
> +}

Thanks,

tglx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/