linux-kernel - Re: [PATCH v1] regulator: Don't error out fixed regulator in regulator_sync

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Message-ID: <YXFnIPXwPuNWM4XG@sirena.org.uk>
Date:   Thu, 21 Oct 2021 14:12:00 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Thierry Reding <treding@...dia.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org
Subject: Re: [PATCH v1] regulator: Don't error out fixed regulator in
 regulator_sync_voltage()

On Thu, Oct 21, 2021 at 02:07:07PM +0300, Dmitry Osipenko wrote:

> Fixed regulator can't change voltage and regulator_sync_voltage() returns
> -EINVAL in this case. Make regulator_sync_voltage() to succeed for a fixed
> regulator.

> +++ b/drivers/regulator/core.c
> @@ -4249,6 +4249,9 @@ int regulator_sync_voltage(struct regulator *regulator)
>  	struct regulator_voltage *voltage = &regulator->voltage[PM_SUSPEND_ON];
>  	int ret, min_uV, max_uV;
>  
> +	if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1)
> +		return 0;
> +
>  	regulator_lock(rdev);

It's unclear why this is checking both fixed_uV and n_voltages.  TBH
this feels like a higher level issue - with normal voltage configuration
we would have noticed that our constraints prevent the voltage changing
and not go as far as trying to actually apply a new configuration.  I
would expect a similar thing to be happening here.

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