Re: [PATCH v3 1/2] hwmon: (pmbus) Add Delta AHE-50DC fan control module driver

From: Guenter Roeck <linux@roeck-us.net>
To: Zev Weiss <zev@bewilderbeest.net>
Cc: linux-hwmon@vger.kernel.org, Jean Delvare <jdelvare@suse.com>,
	openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/2] hwmon: (pmbus) Add Delta AHE-50DC fan control module driver
Date: Tue, 7 Dec 2021 15:15:18 -0800	[thread overview]
Message-ID: <abc2e3bc-3806-dbd3-840c-e19154bc0587@roeck-us.net> (raw)
In-Reply-To: <Ya/X46owU78iVbSO@hatter.bewilderbeest.net>

On 12/7/21 1:53 PM, Zev Weiss wrote:
> On Tue, Dec 07, 2021 at 11:44:01AM PST, Guenter Roeck wrote:
>> On 12/7/21 11:22 AM, Zev Weiss wrote:
>>> On Tue, Dec 07, 2021 at 09:50:15AM PST, Guenter Roeck wrote:
>>>> On Mon, Dec 06, 2021 at 11:15:20PM -0800, Zev Weiss wrote:
>>>>> This device is an integrated module of the Delta AHE-50DC Open19 power
>>>>> shelf.  For lack of proper documentation, this driver has been developed
>>>>> referencing an existing (GPL) driver that was included in a code release
>>>>> from LinkedIn [1].  It provides four fan speeds, four temperatures, and
>>>>> one voltage reading, as well as a handful of warning and fault
>>>>> indicators.
>>>>>
>>>>> [1] https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-kernel/fancontrol-mod/files/fancontrol.c
>>>>>
>>>>
>>>> Hmm, that reference isn't really accurate anymore. I think it would be
>>>> better to just say that the device was found to be PMBus compliant.
>>>
>>> Sure, will do.
>>>
>>
>> Makes me wonder: How do you know that the referenced driver is for Delta AHE-50DC ?
> 
> We'd been waiting for the source code for the software it ships with for a while, and were finally provided with that repo; everything I've observed from the factory software is consistent with the code in that driver.  A sampling:
> 

I assume you mean "Delta AHE-50DC" when you refer to "it".

[ ... ]
>> Can you check this with real hardware, by any chance ?
>>
> 
> If you mean running that code on it, yes -- here's the userspace utility that invokes that library routine:
> 
>      root@bmc-oob:~# fan-util.sh
>      fan1 speed: 7860 RPM
>      fan2 speed: 7860 RPM
>      fan3 speed: 7620 RPM
>      fan4 speed: 7560 RPM
>      temperature1: 29.20 C
>      temperature2: 27.80 C
>      temperature3: 28.50 C
>      temperature4: 30.20 C
>      vin_undervolt_fault: no
>      overtemperature_warning: no
>      fan_fault: no
>      fan_warning: no
>      fan_status: ok
> 

That doesn't really tell me anything in the context of the driver you submitted.
Would it be possible to install your driver and provide the output from the
"sensors" command ? It should match the information from the proprietary
driver/tool.

Thanks,
Guenter