Re: [PATCH] OMAP: DMTIMER: Ack pending interrupt always when stopping a timer

[Kevin Hilman <khilman@deeprootsystems.com>]

Tero Kristo <tero.kristo@nokia.com> writes:

> From: Tero Kristo <tero.kristo@nokia.com>
>
> The kernel timer queue is being run currently from a GP timer running in a one
> shot mode, which works in a way that when it expires, it will also stop.
> Usually during this situation, the interrupt handler will ack the interrupt,
> load a new value to the timer and start it again. During suspend, the
> situation is slightly different, as we disable interrupts just before
> timekeeping is suspended, which leaves a small window where the timer can
> expire before it is stopped, and will leave the interrupt flag pending.
> This pending interrupt will prevent ARM sleep entry, thus now we ack it always
> when we are attempting to stop a timer.
>
> Signed-off-by: Tero Kristo <tero.kristo@nokia.com>

Acked-by: Kevin Hilman <khilman@deeprootsystems.com>

> ---
>  arch/arm/plat-omap/dmtimer.c |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
> index c64875f..023d664 100644
> --- a/arch/arm/plat-omap/dmtimer.c
> +++ b/arch/arm/plat-omap/dmtimer.c
> @@ -541,11 +541,13 @@ void omap_dm_timer_stop(struct omap_dm_timer *timer)
>  		  * timer is stopped
>  		  */
>  		udelay(3500000 / clk_get_rate(timer->fclk) + 1);
> -		/* Ack possibly pending interrupt */
> -		omap_dm_timer_write_reg(timer, OMAP_TIMER_STAT_REG,
> -				OMAP_TIMER_INT_OVERFLOW);
>  #endif
>  	}
> +#ifdef CONFIG_ARCH_OMAP2PLUS
> +	/* Ack possibly pending interrupt */
> +	omap_dm_timer_write_reg(timer, OMAP_TIMER_STAT_REG,
> +			OMAP_TIMER_INT_OVERFLOW);
> +#endif
>  }
>  EXPORT_SYMBOL_GPL(omap_dm_timer_stop);
>  
> -- 
> 1.5.4.3
>
> --
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