From d28c0d84ca40e8cbc5c9f4e94f4ec78469d6c07b Mon Sep 17 00:00:00 2001 From: Frank Li Date: Thu, 20 Jul 2023 09:58:33 -0400 Subject: PCI: layerscape: Add support for link-down notification Add support to pass link-down notification to the endpoint function driver so that it can process the LINK_DOWN event. Link: https://lore.kernel.org/r/20230720135834.1977616-1-Frank.Li@nxp.com Signed-off-by: Frank Li Signed-off-by: Lorenzo Pieralisi Acked-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pci-layerscape-ep.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/pci') diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c index de4c1758a6c3..e0969ff2ddf7 100644 --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c @@ -89,6 +89,7 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id) dev_dbg(pci->dev, "Link up\n"); } else if (val & PEX_PF0_PME_MES_DR_LDD) { dev_dbg(pci->dev, "Link down\n"); + pci_epc_linkdown(pci->ep.epc); } else if (val & PEX_PF0_PME_MES_DR_HRD) { dev_dbg(pci->dev, "Hot reset\n"); } -- cgit v1.2.3 From 17cf8661ee0f065c08152e611a568dd1fb0285f1 Mon Sep 17 00:00:00 2001 From: Xiaowei Bao Date: Thu, 20 Jul 2023 09:58:34 -0400 Subject: PCI: layerscape: Add workaround for lost link capabilities during reset The endpoint controller loses the Maximum Link Width and Supported Link Speed value from the Link Capabilities Register - initially configured by the Reset Configuration Word (RCW) - during a link-down or hot reset event. Address this issue in the endpoint event handler. Link: https://lore.kernel.org/r/20230720135834.1977616-2-Frank.Li@nxp.com Fixes: a805770d8a22 ("PCI: layerscape: Add EP mode support") Signed-off-by: Xiaowei Bao Signed-off-by: Hou Zhiqiang Signed-off-by: Frank Li Signed-off-by: Lorenzo Pieralisi Acked-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pci-layerscape-ep.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/pci') diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c index e0969ff2ddf7..b1faf41a2fae 100644 --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c @@ -45,6 +45,7 @@ struct ls_pcie_ep { struct pci_epc_features *ls_epc; const struct ls_pcie_ep_drvdata *drvdata; int irq; + u32 lnkcap; bool big_endian; }; @@ -73,6 +74,7 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id) struct ls_pcie_ep *pcie = dev_id; struct dw_pcie *pci = pcie->pci; u32 val, cfg; + u8 offset; val = ls_lut_readl(pcie, PEX_PF0_PME_MES_DR); ls_lut_writel(pcie, PEX_PF0_PME_MES_DR, val); @@ -81,6 +83,19 @@ static irqreturn_t ls_pcie_ep_event_handler(int irq, void *dev_id) return IRQ_NONE; if (val & PEX_PF0_PME_MES_DR_LUD) { + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + + /* + * The values of the Maximum Link Width and Supported Link + * Speed from the Link Capabilities Register will be lost + * during link down or hot reset. Restore initial value + * that configured by the Reset Configuration Word (RCW). + */ + dw_pcie_dbi_ro_wr_en(pci); + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, pcie->lnkcap); + dw_pcie_dbi_ro_wr_dis(pci); + cfg = ls_lut_readl(pcie, PEX_PF0_CONFIG); cfg |= PEX_PF0_CFG_READY; ls_lut_writel(pcie, PEX_PF0_CONFIG, cfg); @@ -216,6 +231,7 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev) struct ls_pcie_ep *pcie; struct pci_epc_features *ls_epc; struct resource *dbi_base; + u8 offset; int ret; pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); @@ -252,6 +268,9 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pcie); + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + pcie->lnkcap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + ret = dw_pcie_ep_init(&pci->ep); if (ret) return ret; -- cgit v1.2.3