Date: Sun, 9 Dec 2007 10:50:28 +0100
From: Jean Delvare <khali@linux-fr.org>
To: Mike Houston <mikeserv@bmts.com>
Cc: Adrian Bunk <bunk@stusta.de>, mhoffman@lightlink.com,
       linux-kernel@vger.kernel.org, lm-sensors@lm-sensors.org,
       Bjorn Helgaas <bjorn.helgaas@hp.com>, Adam Belay <ambx1@neo.rr.com>
Subject: Re: [lm-sensors] 2.6.24-rc4 hwmon it87 probe fails
Message-ID: <20071209105028.06ed52a6@hyperion.delvare>
In-Reply-To: <20071208212234.e00b74cd.mikeserv@bmts.com>
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	<20071209000554.GF20441@stusta.de>
	<20071208212234.e00b74cd.mikeserv@bmts.com>
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Hi Mike,

On Sat, 8 Dec 2007 21:22:34 -0500, Mike Houston wrote:
> On Sun, 9 Dec 2007 01:05:54 +0100
> Adrian Bunk <bunk@stusta.de> wrote:
> 
> > On Tue, Dec 04, 2007 at 09:51:54PM -0500, Mike Houston wrote:
> > > I finally got around to testing Linux 2.6.24 (2.6.24-rc4) and
> > > found that the it87 driver fails to probe and consequently, my
> > > sensors no longer work. This was fine with Linux 2.6.23.8 (the
> > > last kernel I was using)
> > > 
> > > The necessary modules load, but:
> > > 
> > > it87: Found IT8718F chip at 0x290, revision 2
> > > it87: in3 is VCC (+5V)
> > > it87 it87.656: Failed to request region 0x290-0x297
> > > it87: probe of it87.656 failed with error -16
> > > 
> > > Coretemp still works.
> > > 
> > > It appears it has something to do with the ioport range being
> > > reserved for some reason:
> > > 
> > > system 00:01: ioport range 0x290-0x29f has been reserved
> 
> > 
> > Thanks for your report.
> > 
> > Please also provide:
> > - dmesg from 2.6.23.8
> > - The output of "cat /proc/ioports" for both kernels
> 
> Thanks Adrian, here is the information you have requested, for
> both kernels (I have 2.6.23.9 now though where it87 still works)
> 
> Linux 2.6.23.9:
> http://www.mikeserv.com/temp/proc_ioports-2.6.23.9.txt
> http://www.mikeserv.com/temp/dmesg-2.6.23.9.txt
> http://www.mikeserv.com/temp/config-2.6.23.9.txt
> 
> Linux 2.6.24-rc4:
> http://www.mikeserv.com/temp/proc_ioports-2.6.24-rc4.txt
> http://www.mikeserv.com/temp/dmesg-2.6.24-rc4.txt

This one shows:

system 00:01: ioport range 0x290-0x29f has been reserved
(...)
system 00:01: ioport range 0x290-0x294 has been reserved

This is clearly not correct as both areas overlap. The second
reservation is responsible for the it87 breakage, because it conflicts
with what the it87 driver later attempts to request (0x290-0x297). The
first is wrong as well (the IT87xxF environment controller I/O area is
8 port wide, not 16) but shouldn't be a problem in practice.

These port reservations weren't happening in 2.6.23.9 according to your
dmesg output for that kernel. I don't know what changed in this area
since 2.6.23.9, maybe Bjorn or Adam (Cc'd) can tell.

Either way, the overlapping areas smell like a BIOS bug, meaning that
you should look for an updated BIOS for your system first.

> http://www.mikeserv.com/temp/config-2.6.24-rc4.txt

-- 
Jean Delvare
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