Re: [External] [PATCH 1/2] platform/x86: thinkpad_acpi: Restore X1 Carbon 9th Gen dual fan quirk

[Mark Pearson <markpearson@lenovo.com>]

On 5/2/22 13:42, Lyude Paul wrote:
> Some answers/comments down below
> 
> On Fri, 2022-04-29 at 21:25 -0400, Mark Pearson wrote:
>> Hi Lyude
>>
>> On 4/29/22 17:14, Lyude Paul wrote:
>>> The new method of probing dual fan support introduced in:
>>>
>>> bf779aaf56ea ("platform/x86: thinkpad_acpi: Add dual fan probe")
>>>
>>> While this commit says this works on the X1 Carbon 9th Gen, it actually
>>> just results in hiding the second fan on my local machine. Additionally,
>>> I'm fairly sure this machine powers on quite often without either of the
>>> two fans spinning.
>>>
>>> So let's fix this by adding back the dual fan quirk for the X1 Carbon 9th
>>> Gen.
>>>
>>> Signed-off-by: Lyude Paul <lyude@redhat.com>
>>> Fixes: bf779aaf56ea ("platform/x86: thinkpad_acpi: Add dual fan probe")
>>> Cc: Mark Pearson <markpearson@lenovo.com>
>>> Cc: Hans de Goede <hdegoede@redhat.com>
>>> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
>>> Cc: Mark Gross <markgross@kernel.org>
>>> Cc: ibm-acpi-devel@lists.sourceforge.net
>>> Cc: platform-driver-x86@vger.kernel.org
>>> ---
>>>  drivers/platform/x86/thinkpad_acpi.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/platform/x86/thinkpad_acpi.c
>>> b/drivers/platform/x86/thinkpad_acpi.c
>>> index c568fae56db2..9067fd0a945c 100644
>>> --- a/drivers/platform/x86/thinkpad_acpi.c
>>> +++ b/drivers/platform/x86/thinkpad_acpi.c
>>> @@ -8699,6 +8699,7 @@ static const struct tpacpi_quirk fan_quirk_table[]
>>> __initconst = {
>>>         TPACPI_Q_LNV3('N', '2', 'E', TPACPI_FAN_2CTL),  /* P1 / X1 Extreme
>>> (1st gen) */
>>>         TPACPI_Q_LNV3('N', '2', 'O', TPACPI_FAN_2CTL),  /* P1 / X1 Extreme
>>> (2nd gen) */
>>>         TPACPI_Q_LNV3('N', '3', '0', TPACPI_FAN_2CTL),  /* P15 (1st gen) /
>>> P15v (1st gen) */
>>> +       TPACPI_Q_LNV3('N', '3', '2', TPACPI_FAN_2CTL),  /* X1 Carbon (9th
>>> gen) */
>>>         TPACPI_Q_LNV3('N', '3', '7', TPACPI_FAN_2CTL),  /* T15g (2nd gen)
>>> */
>>>         TPACPI_Q_LNV3('N', '1', 'O', TPACPI_FAN_NOFAN), /* X1 Tablet (2nd
>>> gen) */
>>>  };
>> I just double checked this on my X1C9 - and it's working correctly. 2nd
>> fan is detected correctly.
>>
>> I'd rather understand why it's not working on your setup then just
>> re-introduce the quirk.
> 
> Of course! I figured as much, it's just easy to start conversations with a
> revert :P
> 
>>
>> What happens on your system when the
>>   res = fan2_get_speed(&speed);
>> is called? If that is failing it means your 2nd fan isn't responding and
>> that's not supposed to happen. Could you let me know if you get an error
>> code, if it happens every boot, etc
>> I assume when the function is called later it works successfully?
> 
> It definitely seems to happen every boot, not sure about the error code it
> returns. I will check and get you this info asap
> 
>>
>> Also please confirm which BIOS and EC version you have.
> 
> BIOS version N32ET75W (1.51) release date 12/02/2021, embedded controller is
> 0.1.32
> 
> 
Thanks!

Along with Thomas' notes I think I've found the problem (though still
bemused why I don't see the problem on my X1C9 and I tested on multiple
platforms previously...so it is somewhat weird).

Working on a fix - will try and have that out for review later today or
tomorrow.

Mark