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Subject: Re: [PATCH 1/2] clocksource/drivers/timer-ti-dm: Prepare to handle
 dra7 timer wrap issue
To:     Tony Lindgren <tony@atomide.com>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     Keerthy <j-keerthy@ti.com>, linux-kernel@vger.kernel.org,
        linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Tero Kristo <kristo@kernel.org>
References: <20210304073737.15810-1-tony@atomide.com>
 <20210304073737.15810-2-tony@atomide.com>
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
Message-ID: <556d55af-0b30-8751-6aef-2e1bb9db1a76@linaro.org>
Date:   Mon, 22 Mar 2021 16:55:31 +0100
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On 04/03/2021 08:37, Tony Lindgren wrote:
> There is a timer wrap issue on dra7 for the ARM architected timer.
> In a typical clock configuration the timer fails to wrap after 388 days.
> 
> To work around the issue, we need to use timer-ti-dm timers instead.
> 
> Let's prepare for adding support for percpu timers by adding a common
> dmtimer_clkevt_init_common() and call it from dmtimer_clockevent_init().
> This patch makes no intentional functional changes.
> 
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---

[ ... ]

> @@ -575,33 +574,60 @@ static int __init dmtimer_clockevent_init(struct device_node *np)
>  	 */
>  	writel_relaxed(OMAP_TIMER_CTRL_POSTED, t->base + t->ifctrl);
>  
> +	if (dev->cpumask == cpu_possible_mask)
> +		irqflags = IRQF_TIMER;
> +	else
> +		irqflags = IRQF_TIMER | IRQF_NOBALANCING;

Can you explain the reasoning behind the test above ?

[ ... ]


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