linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Nicholas Piggin <npiggin@gmail.com>
To: Anton Blanchard <anton@ozlabs.org>
Cc: mikey@neuling.org, paulus@samba.org, oohall@gmail.com,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 2/2] powerpc/time: Only cap decrementer when watchdog is enabled
Date: Sat, 29 Sep 2018 15:16:18 +1000	[thread overview]
Message-ID: <20180929151618.1e15ca4c@roar.ozlabs.ibm.com> (raw)
In-Reply-To: <20180929012607.10204-2-anton@ozlabs.org>

On Sat, 29 Sep 2018 11:26:07 +1000
Anton Blanchard <anton@ozlabs.org> wrote:

> If CONFIG_PPC_WATCHDOG is enabled, we always cap the decrementer to
> 0x7fffffff. As suggested by Nick, add a run time check of the watchdog
> cpumask, so if it is disabled we use the large decrementer.
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---

Thanks for tracking this down. It's a fix for my breakage

a7cba02deced ("powerpc: allow soft-NMI watchdog to cover timer
interrupts with large decrementers")

Taking another look... what I had expected here is the timer subsystem
would have stopped the decrementer device after it processed the timer
and found nothing left. And we should have set DEC to max at that time.

The above patch was really intended to only cover the timer interrupt
itself locking up. I wonder if we need to add

    .set_state_oneshot_stopped = decrementer_shutdown

In our decremementer clockevent device?

Thanks,
Nick

  parent reply	other threads:[~2018-09-29  5:18 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-29  1:26 [PATCH 1/2] powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer Anton Blanchard
2018-09-29  1:26 ` [PATCH 2/2] powerpc/time: Only cap decrementer when watchdog is enabled Anton Blanchard
2018-09-29  4:11   ` kbuild test robot
2018-09-29  5:16   ` Nicholas Piggin [this message]
2018-10-01 22:57     ` Anton Blanchard

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=20180929151618.1e15ca4c@roar.ozlabs.ibm.com \
    --to=npiggin@gmail.com \
    --cc=anton@ozlabs.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mikey@neuling.org \
    --cc=oohall@gmail.com \
    --cc=paulus@samba.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;
as well as URLs for NNTP newsgroup(s).