linux-kernel - Re: [PATCH v3 1/3] clocksource: davinci: only enable clockevents once tim34 is initialized

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 10 Jan 2020 18:56:45 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Bartosz Golaszewski <brgl@...ev.pl>, Sekhar Nori <nsekhar@...com>,
        Thomas Gleixner <tglx@...utronix.de>,
        David Lechner <david@...hnology.com>,
        Kevin Hilman <khilman@...nel.org>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH v3 1/3] clocksource: davinci: only enable clockevents once
 tim34 is initialized

On 10/01/2020 18:16, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
> 
> The DM365 platform has a strange quirk (only present when using ancient
> u-boot - mainline u-boot v2013.01 and later works fine) where if we
> enable the second half of the timer in periodic mode before we do its
> initialization - the time won't start flowing and we can't boot.
> 
> When using more recent u-boot, we can enable the timer, then reinitialize
> it and all works fine.
> 
> To work around this issue only enable clockevents once tim34 is
> initialized i.e. move clockevents_config_and_register() below tim34
> initialization.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>

Shall I take it through my tree?

> ---
>  drivers/clocksource/timer-davinci.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clocksource/timer-davinci.c b/drivers/clocksource/timer-davinci.c
> index 62745c962049..e421946a91c5 100644
> --- a/drivers/clocksource/timer-davinci.c
> +++ b/drivers/clocksource/timer-davinci.c
> @@ -302,10 +302,6 @@ int __init davinci_timer_register(struct clk *clk,
>  		return rv;
>  	}
>  
> -	clockevents_config_and_register(&clockevent->dev, tick_rate,
> -					DAVINCI_TIMER_MIN_DELTA,
> -					DAVINCI_TIMER_MAX_DELTA);
> -
>  	davinci_clocksource.dev.rating = 300;
>  	davinci_clocksource.dev.read = davinci_clocksource_read;
>  	davinci_clocksource.dev.mask =
> @@ -323,6 +319,10 @@ int __init davinci_timer_register(struct clk *clk,
>  		davinci_clocksource_init_tim34(base);
>  	}
>  
> +	clockevents_config_and_register(&clockevent->dev, tick_rate,
> +					DAVINCI_TIMER_MIN_DELTA,
> +					DAVINCI_TIMER_MAX_DELTA);
> +
>  	rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
>  	if (rv) {
>  		pr_err("Unable to register clocksource");
> 


-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog