Re: Fw: suspicious behaviour in pcwd driver.

From: Wim Van Sebroeck (wim_at_iguana.be)
Date: 08/31/05

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    Date:	Wed, 31 Aug 2005 21:00:23 +0200
To: Dave Jones <davej@redhat.com>, linux-kernel@vger.kernel.org

    Hi Dave,

    > drivers/char/watchdog/pcwd.c does this if it detects
    > a temperature out of range..
    >
    > if (temp_panic) {
    > printk (KERN_INFO PFX "Temperature overheat trip!\n");
    > machine_power_off();
    > }
    >
    > Two problems here are..
    >
    > 1. machine_power_off() isn't exported on ppc64. (patch below)
    > 2. that printk will never hit the logs, so the admin will just find
    > a powered off box with no idea what happened.
    > Should we at least sync block devices before doing the power off ?

    First you need to enable the "temp_panic" by setting the WDIOS_TEMPPANIC
    option flag. (I'm curious who actually uses this and when they use this, but
    that is something totally different). And then you need to read the card's
    status before this piece of code will be triggered.
    So in my opinion this isn't used a lott and is simply an option to protect
    your hardware. But your comment is valid: chances that the warning is written
    to the log files is very small.
    So I think that it might indeed be better to sync most devices if that can be
    done in a few seconds...

    Greetings,
    Wim.

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  • Next message: Steve French: "Re: [PATCH] mm: return ENOBUFS instead of ENOMEM in generic_file_buffered_write"