linux-kernel - Re: [PATCH] hwmon: (dell-smm) Disable fan support for Dell XPS13 9333

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Message-ID: <20180608135826.u22gb4ggvgfnifzq@pali>
Date:   Fri, 8 Jun 2018 15:58:26 +0200
From:   Pali Rohár <pali.rohar@...il.com>
To:     Guenter Roeck <linux@...ck-us.net>
Cc:     Helge Eichelberg <kernelorg@...henberg.name>,
        Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] hwmon: (dell-smm) Disable fan support for Dell XPS13 9333

On Friday 08 June 2018 06:51:55 Guenter Roeck wrote:
> On Thu, Jun 07, 2018 at 10:25:42AM +0200, Pali Rohár wrote:
> > On Thursday 07 June 2018 08:04:55 Helge Eichelberg wrote:
> > > On Wed, 6 Jun 2018 17:21:34 +0200
> > > Pali Rohár <pali.rohar@...il.com> wrote:
> > > 
> > > > On Tuesday 05 June 2018 19:38:32 Helge Eichelberg wrote:
> > > > > Calling fan related SMM functions implemented by Dell BIOS firmware on Dell
> > > > > XPS13 9333 freeze kernel for about 500ms. Until Dell fixes it we need to
> > > > > disable fan support for Dell XPS13 9333.
> > > > 
> > > > Hi! Have you reported this firmware bug to Dell?
> > > 
> > > No, I haven't.
> > 
> > Mario (from @Dell) wrote on github, that we should start reporting
> > firmware bugs to Dell as "voice of the customer is the most important".
> > https://github.com/dell/libsmbios/issues/48#issuecomment-393527813
> > 
> > > > Also we should probably match also BIOS version and do not apply this
> > > > blacklist quirk for BIOS versions in which Dell fixed it.
> > > 
> > > The BIOS hasn't been updated since 08/31/2015 and I'm running the latest version (A08). I wonder if Dell cares anymore about the 9333 which has been replaced by the 9343 in early 2015. Nevertheless, should I add a line matching the BIOS version and should it look like this?
> > 
> > Ok, I was in impression that it was fixed or was going to be fixed. This
> > looks like that laptop does not have any support. In this case would
> > need to blacklist it for all bios version and forever. So no match for
> > bios version. Maybe you should re-phrase commit message to indicate that
> > Dell probably does not fix it. Or drop that sentence "Until Dell...".
> > 
> Those would just be assumptions and not add any value to the commit log.
> I don't recall similar comments for previous patches either, and it is not
> as if Dell stopped supporting Linux only recently. I'll apply the patch
> as-is; I don't see value in a respin.

Ok. I have no objections. That was only suggestion. Also you can add my

Reviewed-by: Pali Rohár <pali.rohar@...il.com>

Anyway, if last version of Bios was released 3 years ago, I really doubt
that something is going to be fixed...

> Guenter
> 
> > > DMI_EXACT_MATCH(DMI_BIOS_VERSION, "A08")
> > > 
> > > Helge
> > > 
> > > > > Via "force" module param fan support can be enabled.
> > > > > 
> > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=195751
> > > > > Signed-off-by: Helge Eichelberg <kernelorg@...henberg.name>
> > > > > ---
> > > > >  drivers/hwmon/dell-smm-hwmon.c | 7 +++++++
> > > > >  1 file changed, 7 insertions(+)
> > > > > 
> > > > > diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> > > > > index bf3bb7e1adab..9d3ef879dc51 100644
> > > > > --- a/drivers/hwmon/dell-smm-hwmon.c
> > > > > +++ b/drivers/hwmon/dell-smm-hwmon.c
> > > > > @@ -1074,6 +1074,13 @@ static struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initdata = {
> > > > >  			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
> > > > >  		},
> > > > >  	},
> > > > > +	{
> > > > > +		.ident = "Dell XPS13 9333",
> > > > > +		.matches = {
> > > > > +			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
> > > > > +			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
> > > > > +		},
> > > > > +	},
> > > > >  	{ }
> > > > >  };
> > > > >  
> > > > 
> > > > -- 
> > > > Pali Rohár
> > > > pali.rohar@...il.com
> > 
> > -- 
> > Pali Rohár
> > pali.rohar@...il.com

-- 
Pali Rohár
pali.rohar@...il.com