Re: [PATCH 02/02] clocksource: Start CMT at clocksource resume

From: Thomas Gleixner
Date: Sat Nov 28 2009 - 09:00:42 EST




On Wed, 25 Nov 2009, Magnus Damm wrote:

> From: Magnus Damm <damm@xxxxxxxxxxxxx>
>
> Add code to start the CMT timer on clocksource resume.
>
> This makes sure the timer is started during sysdev_resume().
> Without this patch the clocksource may be read as suspended,
> this after sysdev resume but before platform device resume.

Hmm, don't you have the same situation on suspend ?

platform device suspend stops the clock, but the generic code expects
it to be running until sysdev shutdown.

Another thing is that you now run both, the sysdev and the platform
resume. Is that by design or accident ?

Thanks,

tglx

> Signed-off-by: Magnus Damm <damm@xxxxxxxxxxxxx>
> ---
>
> drivers/clocksource/sh_cmt.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> --- 0001/drivers/clocksource/sh_cmt.c
> +++ work/drivers/clocksource/sh_cmt.c 2009-11-25 16:02:52.000000000 +0900
> @@ -432,6 +432,13 @@ static void sh_cmt_clocksource_disable(s
> sh_cmt_stop(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE);
> }
>
> +static void sh_cmt_clocksource_resume(struct clocksource *cs)
> +{
> + struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
> +
> + sh_cmt_start(p, FLAG_CLOCKSOURCE);
> +}
> +
> static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
> char *name, unsigned long rating)
> {
> @@ -442,6 +449,7 @@ static int sh_cmt_register_clocksource(s
> cs->read = sh_cmt_clocksource_read;
> cs->enable = sh_cmt_clocksource_enable;
> cs->disable = sh_cmt_clocksource_disable;
> + cs->resume = sh_cmt_clocksource_resume;
> cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
> cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
> pr_info("sh_cmt: %s used as clock source\n", cs->name);
>
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