linux-kernel - Re: [PATCH v3 3/7] PCI: imx6: Fix the regulator dump when link never came up

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Date:   Mon, 25 Oct 2021 12:23:48 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Francesco Dolcini <francesco.dolcini@...adex.com>
Cc:     Richard Zhu <hongxing.zhu@....com>, l.stach@...gutronix.de,
        bhelgaas@...gle.com, lorenzo.pieralisi@....com,
        jingoohan1@...il.com, linux-pci@...r.kernel.org, linux-imx@....com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kernel@...gutronix.de
Subject: Re: [PATCH v3 3/7] PCI: imx6: Fix the regulator dump when link never
 came up

On Mon, Oct 25, 2021 at 01:13:12PM +0200, Francesco Dolcini wrote:

> Hello Richard,
> please see this comment from Mark,  https://lore.kernel.org/all/YXaGve1ZJq0DGZ9l@sirena.org.uk/.

> > +		if (imx6_pcie->vpcie
> > +		    && regulator_is_enabled(imx6_pcie->vpcie) > 0)
> > +			regulator_disable(imx6_pcie->vpcie);
> >  		return ret;

I should probably also say that the check for the regulator looks buggy
as well, regulators should only be optional if they can be physically
absent which does not seem likely for PCI devices.  If the driver is not
doing something to reconfigure the hardware to account for a missing
supply this is generally a big warning sign.

I really don't understand why regulator support is so frequently
problematic for PCI controllers.  :(

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