From: tglx@linutronix.de (Thomas Gleixner)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 2/2] clocksource: don't suspend/resume when unused
Date: Fri, 16 Jan 2015 11:23:32 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.11.1501161122320.5526@nanos> (raw)
In-Reply-To: <1421399874-29119-3-git-send-email-alexandre.belloni@free-electrons.com>
On Fri, 16 Jan 2015, Alexandre Belloni wrote:
> There is no point in calling suspend/resume for unused
> clocksources.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> kernel/time/clocksource.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 920a4da58eb0..baea4e42ae90 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -493,7 +493,7 @@ void clocksource_suspend(void)
> struct clocksource *cs;
>
> list_for_each_entry_reverse(cs, &clocksource_list, list)
> - if (cs->suspend)
> + if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED))
> cs->suspend(cs);
This might be dangerous. If the clocksource has no enable/disable
callbacks, but suspend/resume, then you might leave it enabled across
suspend.
Thanks,
tglx
next prev parent reply other threads:[~2015-01-16 10:23 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-16 9:17 [RFC 0/2] clocksource: don't suspend/resume when unused Alexandre Belloni
2015-01-16 9:17 ` [RFC 1/2] clocksource: track usage Alexandre Belloni
2015-01-16 10:39 ` Boris Brezillon
2015-02-02 20:03 ` Kevin Hilman
2015-01-16 9:17 ` [RFC 2/2] clocksource: don't suspend/resume when unused Alexandre Belloni
2015-01-16 10:23 ` Thomas Gleixner [this message]
2015-01-16 10:35 ` Alexandre Belloni
2015-01-16 10:39 ` Daniel Lezcano
2015-01-16 10:48 ` Alexandre Belloni
2015-01-16 10:59 ` Daniel Lezcano
2015-01-16 11:07 ` Alexandre Belloni
2015-01-16 11:45 ` Alexandre Belloni
2015-01-16 11:23 ` Russell King - ARM Linux
2015-01-16 11:28 ` Alexandre Belloni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.11.1501161122320.5526@nanos \
--to=tglx@linutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox