linux-kernel - Re: [PATCH 3/3] hwmon: (dell-smm) Improve warning messages

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Date:   Sun, 21 Aug 2022 21:17:08 +0200
From:   Armin Wolf <W_Armin@....de>
To:     Pali Rohár <pali@...nel.org>
Cc:     jdelvare@...e.com, linux@...ck-us.net, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] hwmon: (dell-smm) Improve warning messages

Am 21.08.22 um 17:46 schrieb Pali Rohár:

> On Sunday 21 August 2022 17:17:13 Armin Wolf wrote:
>> When dell-smm-hwmon is loaded on a machine with a buggy BIOS
>> with the option "force" being enabled, it wrongly prints
>> what the buggy features where disabled. This may cause
>> users to wrongly assume that the driver still protects them
>> from these BIOS bugs even with "force" being enabled.
>> Change the warning message to avoid such a misunderstanding.
> Should not there be also FW_BUG too?

Since the driver itself is unable to detect if a buggy BIOS was fixed,
i would not use FW_BUG here since it may cause confusion if such a message
was printed on an already fixed BIOS.

> I'm thinking more about message, would not it be better to print also
> information if fan support and fan type call is allowed or disallowed
> (based on force argument) when broken BIOS is detected?

Something like "Disabling fan support due to BIOS bugs" and "Enabling fan support despite BIOS bugs"?
The first message could only be a notice message, while the second message could be a warning message.

Armin Wolf

>> Tested on a Dell Inspiron 3505.
>>
>> Signed-off-by: Armin Wolf <W_Armin@....de>
>> ---
>>   drivers/hwmon/dell-smm-hwmon.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
>> index f7bab1a91b93..bf13852afe48 100644
>> --- a/drivers/hwmon/dell-smm-hwmon.c
>> +++ b/drivers/hwmon/dell-smm-hwmon.c
>> @@ -1354,13 +1354,13 @@ static int __init dell_smm_probe(struct platform_device *pdev)
>>   	platform_set_drvdata(pdev, data);
>>
>>   	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
>> -		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
>> +		dev_warn(&pdev->dev, "BIOS has broken fan support\n");
>>   		if (!force)
>>   			data->disallow_fan_support = true;
>>   	}
>>
>>   	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
>> -		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
>> +		dev_warn(&pdev->dev, "BIOS has broken fan type call\n");
>>   		if (!force)
>>   			data->disallow_fan_type_call = true;
>>   	}
>> --
>> 2.30.2
>>