From: slash.tmp@free•fr (Mason)
To: linux-arm-kernel@lists•infradead.org
Subject: schedule_timeout sleeps too long after dividing CPU frequency
Date: Fri, 15 May 2015 11:29:34 +0200 [thread overview]
Message-ID: <5555BC7E.7010601@free.fr> (raw)
In-Reply-To: <20150514144239.GZ2067@n2100.arm.linux.org.uk>
On 14/05/2015 16:42, Russell King - ARM Linux wrote:
> If it's in periodic mode, the update should still be propagated to the
> hardware, assuming the generic time keeping code doesn't produce an
> error.
>
> twd_update_frequency
> `-clockevents_update_freq
> `-__clockevents_update_freq
> `-__clockevents_set_state(, CLOCK_EVT_STATE_PERIODIC)
> `-dev->set_mode (twd_set_mode)
>
> That re-writes the TWD_TIMER_LOAD register based on twd_timer_rate,
> which would have been updated by twd_update_frequency().
>
> The question I posed earlier remains: is clockevents_update_freq()
> failing? We don't know, because we never check its return value.
>
> Another thing to look at is whether we reach twd_set_mode().
>
> Lastly, printing the values of the TWD_TIMER_LOAD and TWD_TIMER_COUNTER
> after twd_set_mode() has written TWD_TIMER_LOAD might provide some
> hints as to what's going on.
I'll have access to the board on Monday.
I'll add printk in strategic places, and report back ASAP.
(I'm considering dropping TWD, and using platform timers.)
Regards.
next prev parent reply other threads:[~2015-05-15 9:29 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-12 14:32 schedule_timeout sleeps too long after dividing CPU frequency Mason
2015-05-12 14:46 ` Viresh Kumar
2015-05-12 15:14 ` Mason
2015-05-12 15:50 ` Russell King - ARM Linux
2015-05-12 16:14 ` Mason
2015-05-13 16:51 ` Mason
2015-05-14 2:13 ` Viresh Kumar
2015-05-14 11:22 ` Mason
2015-05-14 11:54 ` Viresh Kumar
2015-05-14 13:06 ` Mason
2015-05-14 13:53 ` Russell King - ARM Linux
2015-05-14 14:51 ` Mason
2015-05-14 13:59 ` Viresh Kumar
2015-05-14 14:38 ` Viresh Kumar
2015-05-14 14:42 ` Russell King - ARM Linux
2015-05-15 9:29 ` Mason [this message]
2015-05-15 9:51 ` Russell King - ARM Linux
2015-05-15 10:01 ` Viresh Kumar
2015-05-15 10:36 ` Mason
2015-05-15 11:58 ` Russell King - ARM Linux
2015-05-15 12:45 ` Mason
2015-05-15 13:15 ` Russell King - ARM Linux
2015-05-15 13:58 ` Mason
2015-05-15 18:35 ` Mason
2015-05-18 11:24 ` Mason
2015-05-18 11:54 ` Russell King - ARM Linux
2015-05-20 16:21 ` Mason
2015-05-20 18:50 ` Arnd Bergmann
2015-05-20 19:34 ` Mason
2015-05-20 20:14 ` Russell King - ARM Linux
2015-05-20 20:41 ` Mason
2015-05-20 20:52 ` Arnd Bergmann
2015-05-20 21:56 ` Mason
2015-05-20 22:18 ` Arnd Bergmann
2015-05-21 12:35 ` Mason
2015-05-20 23:14 ` Russell King - ARM Linux
2015-05-21 9:56 ` Mason
2015-05-21 10:20 ` Russell King - ARM Linux
2015-05-14 14:48 ` Mason
2015-05-15 4:16 ` Viresh Kumar
2015-05-15 5:07 ` Viresh Kumar
2015-05-15 9:00 ` Russell King - ARM Linux
2015-05-15 9:21 ` Mason
2015-05-15 10:11 ` Mason
2015-05-12 15:23 ` Russell King - ARM Linux
2015-05-12 16:03 ` Mason
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=5555BC7E.7010601@free.fr \
--to=slash.tmp@free$(echo .)fr \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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