linux-kernel - Re: [PATCH v1] regulator: core: Convert warning to debug print

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Message-ID: <4ecd19e5-9dfa-4157-9384-92c722064b2e@linux.ibm.com>
Date:   Thu, 12 Oct 2023 16:45:48 -0500
From:   Ninad Palsule <ninad@...ux.ibm.com>
To:     Mark Brown <broonie@...nel.org>
Cc:     joel@....id.au, eajames@...ux.ibm.com, lgirdwood@...il.com,
        linux-kernel@...r.kernel.org, lakshmiy@...ibm.com
Subject: Re: [PATCH v1] regulator: core: Convert warning to debug print

Hello Mark,

Thanks for the review.

On 10/12/23 12:47, Mark Brown wrote:
> On Thu, Oct 12, 2023 at 12:42:35PM -0500, Ninad Palsule wrote:
>> There are some boards without the vcc regulators for eeprom or other
>> devices. In such cases, we should not see the following warning and
>> this confuses the user. We want to see this only when it is compiled
>> with CONFIG_REGULATOR_DEBUG option.
>> [0.747347] at24 6-0055: supply vcc not found, using dummy regulator
>> [0.752877] pca953x 6-0074: supply vcc not found, using dummy regulator
> This is a warning saying that the firmware description for the system is
> incomplete in case things go wrong later - it is vanishingly unlikely
> that these devices actually do not require supplies, we'd probably have
> heard about it if they did.  If a supply is not described properly we
> may for example decide to power off what we think is an unused supply
> with bad results.

You are right there are regulators for these supplies but they are 
managed by the
hardware hence not added in the device tree. I checked dts/aspeed 
directory and
non of the machine has “vcc-supply” defined and lot of them use eeprom.
Also, I thought that this message is only useful in the lab to indicate 
developer
whether they missed the device tree definition or not but its not useful 
in the
field.  Hence proposed to put it under DEBUG.

Please let me know if I missed something.

Thanks!

~ Ninad