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From: tglx@linutronix.de (Thomas Gleixner)
To: linux-arm-kernel@lists.infradead.org
Subject: RFC: [PATCH] clocksource: tcb: fix min_delta calculation
Date: Thu, 25 Apr 2013 16:21:58 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LFD.2.02.1304251618590.21884@ionos> (raw)
In-Reply-To: <1366722524-25991-1-git-send-email-mkl@pengutronix.de>

On Tue, 23 Apr 2013, Marc Kleine-Budde wrote:
> The commit
> 
>     77cc982 clocksource: use clockevents_config_and_register() where possible
> 
> switches from manually calculating min_delta_ns (and others) and
> clockevents_register_device() to automatic calculation via
> clockevents_config_and_register(). During this conversation the "+ 1" in
> 
>     min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
> 
> was lost. This leads to problems with schedule_delayed_work() with a delay of
> "1". Resulting in the work not scheduled in time.

Errm. How is schedule_delayed_work() related to this?

schedule_delayed_work() is jiffies based and has absolutely nothing to
do with clockevents.
 
> This patch fixes the problem by increasing the min_delta to "2" ticks.

This changelog sucks.

> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/clocksource/tcb_clksrc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
> index 8a61872..7cf6dc7 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -197,7 +197,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>  
>  	clkevt.clkevt.cpumask = cpumask_of(0);
>  
> -	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
> +	clockevents_config_and_register(&clkevt.clkevt, 32768, 2, 0xffff);
>  
>  	setup_irq(irq, &tc_irqaction);
>  }
> -- 
> 1.8.2.rc2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

  parent reply	other threads:[~2013-04-25 14:21 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-12 11:50 [PATCH v2 0/3] Use helper clockevents_config_and_register() Shawn Guo
2013-01-12 11:50 ` [PATCH v2 1/3] clockevents: export clockevents_config_and_register for module use Shawn Guo
2013-01-12 11:50 ` [PATCH v2 2/3] ARM: use clockevents_config_and_register() where possible Shawn Guo
2013-01-12 21:25   ` Jason Cooper
2013-01-12 11:50 ` [PATCH v2 3/3] clocksource: " Shawn Guo
2013-04-23 13:07   ` BUG: " Marc Kleine-Budde
2013-04-23 13:08     ` RFC: [PATCH] clocksource: tcb: fix min_delta calculation Marc Kleine-Budde
2013-04-23 13:11       ` Marc Kleine-Budde
2013-04-23 13:44         ` Shawn Guo
2013-04-23 13:50           ` Marc Kleine-Budde
2013-04-25 13:36       ` Marc Kleine-Budde
2013-04-25 14:18         ` Thomas Gleixner
2013-04-25 14:21       ` Thomas Gleixner [this message]
2013-04-25 14:53         ` Marc Kleine-Budde
2013-06-20 15:00           ` Marc Kleine-Budde
2013-01-12 21:14 ` [PATCH v2 0/3] Use helper clockevents_config_and_register() Arnd Bergmann
2013-01-14 11:23   ` Thomas Gleixner
2013-01-14 18:16     ` Olof Johansson

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