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    SubjectRe: [PATCH v9 5/8] PCI: imx6: Refine the regulator usage
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    Date
    Am Freitag, dem 06.05.2022 um 09:47 +0800 schrieb Richard Zhu:
    > The driver should undo any enables it did itself. The regulator disable
    > shouldn't be basing decisions on regulator_is_enabled().
    >
    > To keep the balance of the regulator usage counter, disable the regulator
    > just behind of imx6_pcie_assert_core_reset() in resume and shutdown.
    >
    > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
    > ---
    > drivers/pci/controller/dwc/pci-imx6.c | 19 +++++++------------
    > 1 file changed, 7 insertions(+), 12 deletions(-)
    >
    > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
    > index 7005a7910003..3ce3993d5797 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);
    > - }
    > }
    >
    > static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)
    > @@ -580,7 +570,7 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
    > struct device *dev = pci->dev;
    > int ret, err;
    >
    > - if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
    > + if (imx6_pcie->vpcie) {
    > ret = regulator_enable(imx6_pcie->vpcie);
    > if (ret) {
    > dev_err(dev, "failed to enable vpcie regulator: %d\n",
    > @@ -653,7 +643,7 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
    > return 0;
    >
    > err_clks:
    > - if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
    > + if (imx6_pcie->vpcie) {
    > ret = regulator_disable(imx6_pcie->vpcie);
    > if (ret)
    > dev_err(dev, "failed to disable vpcie regulator: %d\n",
    > @@ -1026,6 +1016,9 @@ static int imx6_pcie_resume_noirq(struct device *dev)
    > return 0;
    >
    > imx6_pcie_assert_core_reset(imx6_pcie);
    > + if (imx6_pcie->vpcie)
    > + regulator_disable(imx6_pcie->vpcie);
    > +
    This one looks misplaced. Surely you want the regulator to be on when
    resuming the PCIe subsystem. Isn't this just papering over a wrong
    usage count here, because there is no regulator_disable in
    imx6_pcie_suspend_noirq, where I would expect this to happen?

    Regards,
    Lucas

    > imx6_pcie_init_phy(imx6_pcie);
    > imx6_pcie_deassert_core_reset(imx6_pcie);
    > dw_pcie_setup_rc(pp);
    > @@ -1259,6 +1252,8 @@ static void imx6_pcie_shutdown(struct platform_device *pdev)
    >
    > /* bring down link, so bootloader gets clean state in case of reboot */
    > imx6_pcie_assert_core_reset(imx6_pcie);
    > + if (imx6_pcie->vpcie)
    > + regulator_disable(imx6_pcie->vpcie);
    > }
    >
    > static const struct imx6_pcie_drvdata drvdata[] = {


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