linux-kernel - Re: [PATCH] Acer Aspire One Fan Control

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Message-ID: <9ea470500906030352x7d72f3c7s94b12701142a7f7a@mail.gmail.com>
Date:	Wed, 3 Jun 2009 12:52:59 +0200
From:	Borislav Petkov <petkovbb@...glemail.com>
To:	Peter Feuerer <peter@...e.net>
Cc:	LKML <linux-kernel@...r.kernel.org>, lenb@...nel.org,
	Matthew Garrett <mjg59@...f.ucam.org>,
	Maxim Levitsky <maximlevitsky@...il.com>
Subject: Re: [PATCH] Acer Aspire One Fan Control

Hi,

On Wed, Jun 3, 2009 at 10:10 AM, Peter Feuerer <peter@...e.net> wrote:
>>> Hm.. I think it should be clear that the fan is turned off, as soon as
>>> the temperature is below the fanoff temperature. In my opinion printing this
>>> message would be a case for a "verbose==2" verbose mode :)
>>
>> My reasoning was that because this is called from sysfs and the user
>> sees nothing happening even if he'd turned off the fan by calling
>> .set_cur_state that it might be useful to tell him why.
>
> But the user isn't allowed to change the fan state from userspace anymore.

Actually, Pavel wanted to have that functionality...

> If you try to change the fan state from userspace you'll get the "changing
> fan state is not allowed" message.

By the way, the system log is being polluted with that message after a
suspend/resume cycle:

[99027.020952] acerhdf: failed reading fan state, disabling kernelmode.
[99027.520172] ACPI: EC: missing confirmations, switch off interrupt mode.
[99047.672142] acerhdf: changing fan state is not allowed
[99057.696151] acerhdf: changing fan state is not allowed
[99067.720125] acerhdf: changing fan state is not allowed
[99077.744164] acerhdf: changing fan state is not allowed
[99087.796127] acerhdf: changing fan state is not allowed
[99097.820147] acerhdf: changing fan state is not allowed
[99107.844136] acerhdf: changing fan state is not allowed
[99117.908153] acerhdf: changing fan state is not allowed
[99127.932155] acerhdf: changing fan state is not allowed
[99137.123893] [drm:i915_get_vblank_counter] *ERROR* trying to get
vblank count for disabled pipe 0
[99137.956075] acerhdf: changing fan state is not allowed
[99147.980158] acerhdf: changing fan state is not allowed
[99158.004180] acerhdf: changing fan state is not allowed
[99168.028148] acerhdf: changing fan state is not allowed
[99170.207885] [drm:i915_get_vblank_counter] *ERROR* trying to get
vblank count for disabled pipe 0
[99178.052149] acerhdf: changing fan state is not allowed
[99188.076149] acerhdf: changing fan state is not allowed
[99198.100148] acerhdf: changing fan state is not allowed
[99208.124150] acerhdf: changing fan state is not allowed
[99210.558715] acerhdf: kernelmode ON
[99210.581161] acerhdf: changing fan state is not allowed

because the suspend/resume cycle is causing the EC error message
above. In that case, you shouldn't probably switch off kernel mode but
unregister the driver completely until the EC error is fixed (if ever)... Hmm...

-- 
Regards/Gruss,
Boris
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