Messages in this thread | | | Date | Mon, 13 Jun 2022 17:21:19 -0500 | From | Bjorn Helgaas <> | Subject | Re: [PATCH v10 6/7] PCI: imx6: Mark the link down as none fatal error |
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On Mon, Jun 13, 2022 at 04:55:37PM +0800, Richard Zhu wrote: > let the driver probe successfully, return zero in imx6_pcie_start_link() > when PCIe link is down. > > Because i.MX PCIe doesn't support hot-plug feature. > In this link down scenario, only start the PCIe link training in resume > when the link is up before system suspend to avoid the long latency in > the link training period.
This looks like two changes that should be separate patches:
1) Make driver probe successful even if link is down.
2) Reduce resume time by only starting the link if it was up before suspend.
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> > --- > drivers/pci/controller/dwc/pci-imx6.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index c02748393aac..ac6ec2d691a0 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -67,6 +67,7 @@ struct imx6_pcie { > struct dw_pcie *pci; > int reset_gpio; > bool gpio_active_high; > + bool link_is_up; > struct clk *pcie_bus; > struct clk *pcie_phy; > struct clk *pcie_inbound_axi; > @@ -845,7 +846,9 @@ 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; > > if (pci->link_gen == 2) { > /* Allow Gen2 mode after the link is up. */ > @@ -881,11 +884,14 @@ 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"); > } > > + imx6_pcie->link_is_up = true; > tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS); > return 0; > @@ -895,7 +901,7 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), > dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); > imx6_pcie_reset_phy(imx6_pcie); > - return ret; > + return 0; > } > > static int imx6_pcie_host_init(struct pcie_port *pp) > @@ -1022,10 +1028,8 @@ static int imx6_pcie_resume_noirq(struct device *dev) > imx6_pcie_init_phy(imx6_pcie); > imx6_pcie_deassert_core_reset(imx6_pcie); > dw_pcie_setup_rc(pp); > - > - ret = imx6_pcie_start_link(imx6_pcie->pci); > - if (ret < 0) > - dev_info(dev, "pcie link is down after resume.\n"); > + if (imx6_pcie->link_is_up) > + imx6_pcie_start_link(imx6_pcie->pci); > > return 0; > } > -- > 2.25.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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