Messages in this thread | | | From | Hongxing Zhu <> | Subject | RE: [PATCH v7 7/8] PCI: imx6: Disable enabled clocks and regulators after link is down | Date | Thu, 24 Feb 2022 07:51:07 +0000 |
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> -----Original Message----- > From: Bjorn Helgaas <helgaas@kernel.org> > Sent: 2022年2月24日 1:50 > To: Hongxing Zhu <hongxing.zhu@nxp.com> > Cc: l.stach@pengutronix.de; bhelgaas@google.com; broonie@kernel.org; > lorenzo.pieralisi@arm.com; jingoohan1@gmail.com; festevam@gmail.com; > francesco.dolcini@toradex.com; linux-pci@vger.kernel.org; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; > kernel@pengutronix.de; dl-linux-imx <linux-imx@nxp.com> > Subject: Re: [PATCH v7 7/8] PCI: imx6: Disable enabled clocks and regulators > after link is down > > In subject, > > s/Disable enabled clocks/Disable clocks/ Okay, would be updated later. Thanks.
> > On Wed, Feb 16, 2022 at 02:21:02PM +0800, Richard Zhu wrote: > > Since i.MX PCIe doesn't support the hot-plug, and to save power > > consumption as much as possible. Return error and disable the enabled > > clocks and regulators when link is down,. > > Maybe: > > Since i.MX PCIe doesn't support hot-plug, reduce power consumption > as much as possible by disabling clocks and regulators and returning > error when the link is down. Okay.
> > > Add a new host_exit() callback for i.MX PCIe driver to disable the > > enabled clocks, regulators and so on in the error handling after > > host_init is finished. > > > > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> > > --- > > drivers/pci/controller/dwc/pci-imx6.c | 30 > > ++++++++++++++++++++++++--- > > 1 file changed, 27 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > b/drivers/pci/controller/dwc/pci-imx6.c > > index 242d8ef73c1e..fe671e88ec93 100644 > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > @@ -848,7 +848,9 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > > /* Start LTSSM. */ > > imx6_pcie_ltssm_enable(dev); > > > > - dw_pcie_wait_for_link(pci); > > + ret = dw_pcie_wait_for_link(pci); > > + if (ret) > > + goto err_reset_phy; > > These labels look wrong now, since you no longer reset the PHY at > err_reset_phy. You're right. Would be replaced by "err_out" later. Thanks.
Best Regards Richard Zhu
> > > if (pci->link_gen == 2) { > > /* Allow Gen2 mode after the link is up. */ @@ -884,7 +886,9 @@ > > static int imx6_pcie_start_link(struct dw_pcie *pci) > > } > > > > /* Make sure link training is finished as well! */ > > - dw_pcie_wait_for_link(pci); > > + ret = dw_pcie_wait_for_link(pci); > > + if (ret) > > + goto err_reset_phy; > > } else { > > dev_info(dev, "Link: Gen2 disabled\n"); > > } > > @@ -897,7 +901,6 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > > dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", > > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > > - imx6_pcie_reset_phy(imx6_pcie); > > return ret; > > } > > > > @@ -921,8 +924,29 @@ static int imx6_pcie_host_init(struct pcie_port *pp) > > return 0; > > } > > > > +static void imx6_pcie_host_exit(struct pcie_port *pp) { > > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > > + struct device *dev = pci->dev; > > + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci); > > + > > + imx6_pcie_reset_phy(imx6_pcie); > > + imx6_pcie_clk_disable(imx6_pcie); > > + switch (imx6_pcie->drvdata->variant) { > > + case IMX8MM: > > + if (phy_power_off(imx6_pcie->phy)) > > + dev_err(dev, "unable to power off phy\n"); > > + break; > > + default: > > + break; > > + } > > + if (imx6_pcie->vpcie) > > + regulator_disable(imx6_pcie->vpcie); > > +} > > + > > static const struct dw_pcie_host_ops imx6_pcie_host_ops = { > > .host_init = imx6_pcie_host_init, > > + .host_exit = imx6_pcie_host_exit, > > }; > > > > static const struct dw_pcie_ops dw_pcie_ops = { > > -- > > 2.25.1 > >
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