RE: [PATCH v6 5/8] PCI: imx6: Refine the regulator usage

[Hongxing Zhu]

> -----Original Message-----
> From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
> Sent: 2022年2月12日 0:28
> To: Hongxing Zhu <hongxing.zhu@xxxxxxx>
> Cc: l.stach@xxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx; broonie@xxxxxxxxxx;
> lorenzo.pieralisi@xxxxxxx; jingoohan1@xxxxxxxxx; festevam@xxxxxxxxx;
> linux-pci@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> kernel@xxxxxxxxxxxxxx
> Subject: Re: [PATCH v6 5/8] PCI: imx6: Refine the regulator usage
> 
> Hello Richard,
> 
> On Tue, Feb 08, 2022 at 11:25:32AM +0800, Richard Zhu wrote:
> > The driver should undo any enables it did itself. The regulator
> > disable shouldn't be basing decisions on regulator_is_enabled().
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> > ---
> >  drivers/pci/controller/dwc/pci-imx6.c | 14 ++------------
> >  1 file changed, 2 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 0aca762d88a3..e165ad00989c 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -369,8 +369,6 @@ static int imx6_pcie_attach_pd(struct device *dev)
> >
> >  static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
> > {
> > -	struct device *dev = imx6_pcie->pci->dev;
> > -
> >  	switch (imx6_pcie->drvdata->variant) {
> >  	case IMX7D:
> >  	case IMX8MQ:
> > @@ -400,14 +398,6 @@ static void imx6_pcie_assert_core_reset(struct
> imx6_pcie *imx6_pcie)
> >  				   IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
> >  		break;
> >  	}
> > -
> > -	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
> > -		int ret = regulator_disable(imx6_pcie->vpcie);
> > -
> > -		if (ret)
> > -			dev_err(dev, "failed to disable vpcie regulator: %d\n",
> > -				ret);
> > -	}
> 
> This commit is not just cleaning up the regulator usage as you state in the
> commit message, this is removing the vpcie regulator_disable from
> imx6_pcie_assert_core_reset().
> 
> I would not do it, this is called for example on the shutdown callback where it
> makes sense.
Hi Francesco:
Thanks for your review.
Do you means that we should keep regulator_disable() here?
Okay, I would change it later.

Best Regards
Richard Zhu

> 
> Francesco