From: Giovanni Mascellani <gio@debian.org>
To: kernelnewbies@kernelnewbies.org
Subject: Re: [PATCH] hwmon: (dell-smm-hwmon) Disable BIOS fan control upon loading
Date: Wed, 13 Nov 2019 09:31:15 +0100 [thread overview]
Message-ID: <dcd0379b-2b84-b480-f6f1-841275ab2e8d@debian.org> (raw)
In-Reply-To: <CAHFW8PT9PK83JKAegaZWNLk52N7Zk_t+=qyNSoyt3V3W6FMSww@mail.gmail.com>
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Hi,
Il 13/11/19 09:15, Ilie Halip ha scritto:
> The module parameter value, when specified, should be used.
> When it is not specified, you probably still want to check the
> dmi_table.
Hmm, that does not solve the problem mentioned by Valdis: if there is no
userspace daemon piloting the fan, the module should not do anything, so
that the BIOS still has a chance to regulate the fan (which might not
mean much: the BIOS seems to be very buggy, and sometimes it won't speed
up the fan even when all the cores are busy compiling C++ for minutes
and very hot; but at least that's not the kernel module's fault).
Maybe another approach is to only disable the BIOS code when the first
SET_FAN command is received, so I know that there is someone in
userspace. Of course I am not protected from the possibility that the
userspace daemon sends wrong commands or crashes, but I am not protected
anyway. I rely on other lower level measures (such as, the CPU powering
down then it crosses a critical threshold) to protect the hardware from
this scenario.
Is this a reasonable solution?
> Coincidentally, I have a Dell laptop model which might be
> affected by a similar issue. I'd be happy to test your patch.
That would be good!
Thanks, Giovanni.
--
Giovanni Mascellani <g.mascellani@gmail.com>
Postdoc researcher - Université Libre de Bruxelles
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prev parent reply other threads:[~2019-11-13 8:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 21:41 [PATCH] hwmon: (dell-smm-hwmon) Disable BIOS fan control upon loading Giovanni Mascellani
2019-11-12 22:28 ` Valdis Klētnieks
2019-11-13 7:17 ` Giovanni Mascellani
2019-11-13 8:15 ` Ilie Halip
2019-11-13 8:31 ` Giovanni Mascellani [this message]
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