> -----Original Message-----
> From: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Sent: 2022年2月24日 1:50
> To: Hongxing Zhu <hongxing.zhu@xxxxxxx>
> Cc: l.stach@xxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx; broonie@xxxxxxxxxx;
> lorenzo.pieralisi@xxxxxxx; jingoohan1@xxxxxxxxx; festevam@xxxxxxxxx;
> francesco.dolcini@xxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> kernel@xxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>
> 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@xxxxxxx>
> > ---
> > 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
> >
