From 275e88b06a277ccf89d9c471a777e9b4f8c552b0 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Fri, 18 Dec 2020 08:39:05 -0600 Subject: [PATCH] PCI: tegra: Fix host link initialization Commit b9ac0f9dc8ea ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common code") broke enumeration of downstream devices on Tegra: In non-working case (next-20201211): 0001:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad2 (rev a1) 0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13) 0005:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad0 (rev a1) In working case (v5.10-rc7): 0001:00:00.0 PCI bridge: Molex Incorporated Device 1ad2 (rev a1) 0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13) 0005:00:00.0 PCI bridge: Molex Incorporated Device 1ad0 (rev a1) 0005:01:00.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab) 0005:02:02.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab) 0005:03:00.0 USB controller: PLX Technology, Inc. Device 3380 (rev ab) The problem seems to be dw_pcie_setup_rc() is now called twice before and after the link up handling. The fix is to move Tegra's link up handling to .start_link() function like other DWC drivers. Tegra is a bit more complicated than others as it re-inits the whole DWC controller to retry the link. With this, the initialization ordering is restored to match the prior sequence. Fixes: b9ac0f9dc8ea ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common code") Link: https://lore.kernel.org/r/20201218143905.1614098-1-robh@kernel.org Reported-by: Mian Yousaf Kaukab Tested-by: Mian Yousaf Kaukab Signed-off-by: Rob Herring Signed-off-by: Bjorn Helgaas Cc: Lorenzo Pieralisi Cc: Thierry Reding Cc: Jonathan Hunter Cc: Vidya Sagar --- drivers/pci/controller/dwc/pcie-tegra194.c | 55 ++++++++++++---------- 1 file changed, 29 insertions(+), 26 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 5597b2a49598..6fa216e52d14 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -853,12 +853,14 @@ static void config_gen3_gen4_eq_presets(struct tegra_pcie_dw *pcie) dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val); } -static void tegra_pcie_prepare_host(struct pcie_port *pp) +static int tegra_pcie_dw_host_init(struct pcie_port *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct tegra_pcie_dw *pcie = to_tegra_pcie(pci); u32 val; + pp->bridge->ops = &tegra_pci_ops; + if (!pcie->pcie_cap_base) pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci, PCI_CAP_ID_EXP); @@ -907,10 +909,24 @@ static void tegra_pcie_prepare_host(struct pcie_port *pp) dw_pcie_writel_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF, val); } - dw_pcie_setup_rc(pp); - clk_set_rate(pcie->core_clk, GEN4_CORE_CLK_FREQ); + return 0; +} + +static int tegra_pcie_dw_start_link(struct dw_pcie *pci) +{ + u32 val, offset, speed, tmp; + struct tegra_pcie_dw *pcie = to_tegra_pcie(pci); + struct pcie_port *pp = &pci->pp; + bool retry = true; + + if (pcie->mode == DW_PCIE_EP_TYPE) { + enable_irq(pcie->pex_rst_irq); + return 0; + } + +retry_link: /* Assert RST */ val = appl_readl(pcie, APPL_PINMUX); val &= ~APPL_PINMUX_PEX_RST; @@ -929,19 +945,10 @@ static void tegra_pcie_prepare_host(struct pcie_port *pp) appl_writel(pcie, val, APPL_PINMUX); msleep(100); -} - -static int tegra_pcie_dw_host_init(struct pcie_port *pp) -{ - struct dw_pcie *pci = to_dw_pcie_from_pp(pp); - struct tegra_pcie_dw *pcie = to_tegra_pcie(pci); - u32 val, tmp, offset, speed; - - pp->bridge->ops = &tegra_pci_ops; - - tegra_pcie_prepare_host(pp); if (dw_pcie_wait_for_link(pci)) { + if (!retry) + return 0; /* * There are some endpoints which can't get the link up if * root port has Data Link Feature (DLF) enabled. @@ -975,10 +982,11 @@ static int tegra_pcie_dw_host_init(struct pcie_port *pp) val &= ~PCI_DLF_EXCHANGE_ENABLE; dw_pcie_writel_dbi(pci, offset, val); - tegra_pcie_prepare_host(pp); + tegra_pcie_dw_host_init(pp); + dw_pcie_setup_rc(pp); - if (dw_pcie_wait_for_link(pci)) - return 0; + retry = false; + goto retry_link; } speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) & @@ -998,15 +1006,6 @@ static int tegra_pcie_dw_link_up(struct dw_pcie *pci) return !!(val & PCI_EXP_LNKSTA_DLLLA); } -static int tegra_pcie_dw_start_link(struct dw_pcie *pci) -{ - struct tegra_pcie_dw *pcie = to_tegra_pcie(pci); - - enable_irq(pcie->pex_rst_irq); - - return 0; -} - static void tegra_pcie_dw_stop_link(struct dw_pcie *pci) { struct tegra_pcie_dw *pcie = to_tegra_pcie(pci); @@ -2215,6 +2214,10 @@ static int tegra_pcie_dw_resume_noirq(struct device *dev) goto fail_host_init; } + ret = tegra_pcie_dw_start_link(&pcie->pci); + if (ret < 0) + goto fail_host_init; + /* Restore MSI interrupt vector */ dw_pcie_writel_dbi(&pcie->pci, PORT_LOGIC_MSI_CTRL_INT_0_EN, pcie->msi_ctrl_int); -- 2.20.1