Re: [PATCH] i8k: Add support for temperature sensor labels

[Guenter Roeck <linux@roeck-us.net>]

On 11/29/2014 10:27 AM, Gabriele Mazzotta wrote:
> On Saturday 29 November 2014 18:18:18 Pali Rohár wrote:
>> On Saturday 29 November 2014 18:07:19 Gabriele Mazzotta wrote:
>>> On Saturday 29 November 2014 17:09:35 Pali Rohár wrote:
>>>> On Saturday 29 November 2014 17:04:07 Pali Rohár wrote:
>>>>> This patch adds labels for temperature sensors if SMM
>>>>> function with EAX register 0x11a3 reports it. These
>>>>> informations was taken from DOS binary NBSVC.MDM.
>>>>>
>>>>> Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
>>>>> ---
>>>>>
>>>>>   drivers/char/i8k.c |  110
>>>>>
>>>>> +++++++++++++++++++++++++++++++++++++++++----------- 1
>>>>> file changed, 88 insertions(+), 22 deletions(-)
>>>>
>>>> I tested patch on Latitude E6440 and i8k CPU & GPU temps
>>>> match intel coretemp & amd radeion temps.
>>>>
>>>> But I would like if somebody with other Dell laptop can test
>>>> if temperature labels are correct...
>>>
>>> I tested it on my XPS13 9333, here what sensors outputs:
>>>
>>> acpitz-virtual-0
>>> Adapter: Virtual device
>>> temp1:        +27.8°C  (crit = +105.0°C)
>>> temp2:        +29.8°C  (crit = +105.0°C)
>>>
>>> coretemp-isa-0000
>>> Adapter: ISA adapter
>>> Physical id 0:  +62.0°C  (high = +100.0°C, crit = +100.0°C)
>>> Core 0:         +62.0°C  (high = +100.0°C, crit = +100.0°C)
>>> Core 1:         +61.0°C  (high = +100.0°C, crit = +100.0°C)
>>>
>>> i8k-virtual-0
>>> Adapter: Virtual device
>>> fan2:           0 RPM
>>> CPU:          +62.0°C
>>> Ambient:      +49.0°C
>>> SODIMM:       +46.0°C
>>> temp4:            N/A
>>>
>>> CPU seems to be correct, but I can't say anything on Ambient
>>> and SODIMM. temp4 is constantly equal to SODIMM without this
>>> patch, so I'd say N/A is correct.
>>>
>>>
>>> Gabriele
>>
>> It is unknown for me how to directly read Ambient and SODIMM
>> temperatures (without Dell SMM functions). So we can only trust
>> Dell SMM that it reporting correct values and type is really
>> Ambient and SODIMM.
>>
>> And about temp4:
>>
>> Label is not set when SMM function fails. Original DOS NBSVC.MDM
>> just ignore all sensors for which SMM type function fails.
>>
>> This patch should not disable any sensor, so if you previously
>> had some value (<= 128°C) and now not, then there is some bug.
>>
>> Can you test this patch?
>> https://git.kernel.org/cgit/linux/kernel/git/gregkh/char-misc.git/comm
>> it/?h=char-misc-testing&id=723493ca59c8d81fed3e7f261165fee493a29ffa
>>
>> It is possible that same value is caused by incorrect use of
>> prev[] array which should be fixed by above patch.
>>
>> Can you test i8k with and without above patch?
>
> I did some more tests. What I think is happening is that temp4_label
> returns -22, so I sensors prints N/A without actually reading temp4_input.
>
> I'm doing some tests to understand what's going on with temp4_input.
> It reports the value of the last temp*_input I read. If I read it right
> after I loaded i8k, I get an error (-22).
>
> The same doesn't happen for temp3_label, which constantly returns -22.
>
> I already had https://git.kernel.org/cgit/linux/kernel/git/gregkh/char-misc.git/commit/?h=char-misc-testing&id=723493ca59c8d81fed3e7f261165fee493a29ffa
> applied. Without it, things seem not to change much.
> I either get an error (-22) or some incorrect values (for now always
> 1000) when I read temp4_input right after i8k was loaded.
> Once I read some other temp*_input, I always get the last value read.
>
I am seeing exactly the same behavior on an XPS13.

Guenter