> -----Original Message----- > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > Sent: 2022年6月16日 7:31 > To: Hongxing Zhu <hongxing.zhu@xxxxxxx>; Lucas Stach > <l.stach@xxxxxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Mark Brown > <broonie@xxxxxxxxxx>; Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>; Fabio > Estevam <festevam@xxxxxxxxx>; Francesco Dolcini > <francesco.dolcini@xxxxxxxxxxx> > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; dl-linux-imx > <linux-imx@xxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Subject: Re: [PATCH v12 09/13] PCI: imx6: Turn off regulator when system is in > suspend mode > > On Wed, Jun 15, 2022 at 06:15:47PM -0500, Bjorn Helgaas wrote: > > From: Richard Zhu <hongxing.zhu@xxxxxxx> > > > > The driver should undo any enables it did itself. The regulator > > disable shouldn't be basing decisions on regulator_is_enabled(). > > > > Move the regulator_disable to the suspend function, turn off regulator > > when the system is in suspend mode. > > > > To keep the balance of the regulator usage counter, disable the > > regulator in shutdown. > > > > Link: > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore > > .kernel.org%2Fr%2F1655189942-12678-6-git-send-email-hongxing.z&d > at > > > a=05%7C01%7Chongxing.zhu%40nxp.com%7C8dea46d908d34cb4825808da4 > f270eaf% > > > 7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6379093264156415 > 35%7CUnkn > > > own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1 > haWwi > > > LCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=tqzlcCmtSkUNxNzJ0Fr5o > CR3X2CTH > > 4dwUJS4NXt5KRc%3D&reserved=0 > > hu@xxxxxxx > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > --- > > 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 6eddd0b5f628..537b8a2e0e3b 100644 > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > @@ -670,8 +670,6 @@ static void imx6_pcie_clk_disable(struct imx6_pcie > > *imx6_pcie) > > > > 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: > > @@ -702,14 +700,6 @@ static void imx6_pcie_assert_core_reset(struct > imx6_pcie *imx6_pcie) > > 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); > > - } > > - > > /* Some boards don't have PCIe reset GPIO. */ > > if (gpio_is_valid(imx6_pcie->reset_gpio)) > > gpio_set_value_cansleep(imx6_pcie->reset_gpio, > > @@ -722,7 +712,7 @@ 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", @@ > -796,7 > > +786,7 @@ 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", @@ > -1023,6 > > +1013,9 @@ static int imx6_pcie_suspend_noirq(struct device *dev) > > break; > > } > > > > + if (imx6_pcie->vpcie) > > + regulator_disable(imx6_pcie->vpcie); > > This is a little bit ugly because imx6_pcie_suspend_noirq() and > imx6_pcie_resume_noirq() are not symmetric. > > We call regulator_disable() directly here in imx6_pcie_suspend_noirq(), but the > corresponding regulator_enable() is buried in imx6_pcie_deassert_core_reset(). > > It would be nicer if the suspend and resume paths looked more similar, as > rockchip_pcie_suspend_noirq() and rockchip_pcie_resume_noirq() do, for > example. Yes, it is. The regulator_disable()/regulator_enable() are not invoked symmetrically. In the original codes, the regulator_disable() is contained in imx6_pcie_assert_core_reset() and with _eanbled() check. And regulator_enable() is embedded in imx6_pcie_deassert_core_reset(). Both the regulator disable and enable are invoked in resume before. I move the regulator_disable to suspend mode refer to Lucas' comments. Refer to the current situation, how about to move the regulator_disable() out of imx6_pcie_deassert_core_reset() too? Best Regards Richard Zhu > > > return 0; > > } > > > > @@ -1269,6 +1262,8 @@ 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[] = { > > -- > > 2.25.1 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > > https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists > > .infradead.org%2Fmailman%2Flistinfo%2Flinux-arm-kernel&data=05%7 > C0 > > > 1%7Chongxing.zhu%40nxp.com%7C8dea46d908d34cb4825808da4f270eaf%7 > C686ea1 > > > d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637909326415641535%7CUnk > nown%7CTW > > > FpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXV > CI6 > > > Mn0%3D%7C3000%7C%7C%7C&sdata=xjn3jX7ub9%2BX%2BAJQ7YPecV5 > ujkzLAPXkY > > hcieKs%2BKqg%3D&reserved=0
