linux-kernel - Re: [PATCH 2/2] hwmon: chipcap2: disable sensor if request ready irq fails

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Message-ID: <f6034baa-3a1c-4bd3-8cf2-cd197e8a0945@gmail.com>
Date: Mon, 12 Aug 2024 22:48:06 +0200
From: Javier Carrasco <javier.carrasco.cruz@...il.com>
To: Guenter Roeck <linux@...ck-us.net>, Jean Delvare <jdelvare@...e.com>
Cc: linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] hwmon: chipcap2: disable sensor if request ready irq
 fails

On 12/08/2024 22:08, Guenter Roeck wrote:
> On 8/12/24 12:59, Javier Carrasco wrote:
>> On 12/08/2024 18:49, Guenter Roeck wrote:
>>> On 8/12/24 08:43, Javier Carrasco wrote:
>>>> This check is carried out after getting the regulator, and the device
>>>> can be disabled if an error occurs.
>>>>
>>>
>>> I do not see a possible path for a call to cc2_enable() at this point,
>>> meaning the regulator won't ever be enabled. Please provide a better
>>> explanation why this patch would be necessary.
>>>
>>> Guenter
>>>
>>
>> Hi Guenter,
>>
>> this patch enforces the state where the dedicated regulator is disabled,
>> no matter what the history of the regulator was. If a previous
>> regulator_disable() failed, it would still be desirable that the
>> regulator gets disabled the next time the driver is probed (i.e. a new
>> attempt to disable it on failure).
>> cc2_disable() checks first if the regulator is enabled to avoid any
>> imbalance.
>>
> 
> That is very theoretic. Sorry, I am not going to accept this patch.
> 
> Guenter
> 

I get your point, but given that this device requires a dedicated
regulator, I believe it makes sense that it tries to disable it whenever
possible if it's not going to be used. I think that makes more sense
that just returning an error value without even making sure that de
regulator was disabled, doesn't it?

Of course this is not a killer feature, and I don't want to make you
waste much time with it. But I think the dedicated regulator should be
shut down in all error paths, whatever status it had before.

If that does not sound convincing, then I won't argue any longer. Please
take a look at the first patch of the series in any case, which is not a
killer feature either, but cleaner than the current implementation.

Thanks and best regards,
Javier Carrasco