From eff0306b109f2d611e44f0155b0324f6cfec3ef4 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Sat, 1 Nov 2025 09:59:42 +0530 Subject: PCI: meson: Fix parsing the DBI register region First of all, the driver was parsing the 'dbi' register region as 'elbi'. This was due to DT mistakenly passing 'dbi' as 'elbi'. Since the DT is now fixed to supply 'dbi' region, this driver can rely on the DWC core driver to parse and map it. However, to support the old DTs, if the 'elbi' region is found in DT, parse and map the region as both 'dw_pcie::elbi_base' as 'dw_pcie::dbi_base'. This will allow the driver to work with both broken and fixed DTs. Also, skip parsing the 'elbi' region in DWC core if 'pci->elbi_base' was already populated. Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver") Fixes: c96992a24bec ("PCI: dwc: Add support for ELBI resource mapping") Reported-by: Linnaea Lavia Closes: https://lore.kernel.org/linux-pci/DM4PR05MB102707B8CDF84D776C39F22F2C7F0A@DM4PR05MB10270.namprd05.prod.outlook.com/ Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Tested-by: Neil Armstrong # on Bananapi-M2S Reviewed-by: Neil Armstrong Cc: stable@vger.kernel.org # 6.2 Link: https://patch.msgid.link/20251101-pci-meson-fix-v1-3-c50dcc56ed6a@oss.qualcomm.com --- drivers/pci/controller/dwc/pcie-designware.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index c644216995f6..06eca858eb1b 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -168,11 +168,13 @@ int dw_pcie_get_resources(struct dw_pcie *pci) } /* ELBI is an optional resource */ - res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi"); - if (res) { - pci->elbi_base = devm_ioremap_resource(pci->dev, res); - if (IS_ERR(pci->elbi_base)) - return PTR_ERR(pci->elbi_base); + if (!pci->elbi_base) { + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi"); + if (res) { + pci->elbi_base = devm_ioremap_resource(pci->dev, res); + if (IS_ERR(pci->elbi_base)) + return PTR_ERR(pci->elbi_base); + } } /* LLDD is supposed to manually switch the clocks and resets state */ -- cgit v1.2.3 From a00bba406b5a682764ecb507e580ca8159196aa3 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 18 Nov 2025 15:42:15 -0600 Subject: PCI: dwc: Advertise L1 PM Substates only if driver requests it L1 PM Substates require the CLKREQ# signal and may also require device-specific support. If CLKREQ# is not supported or driver support is lacking, enabling L1.1 or L1.2 may cause errors when accessing devices, e.g., nvme nvme0: controller is down; will reset: CSTS=0xffffffff, PCI_STATUS=0x10 If the kernel is built with CONFIG_PCIEASPM_POWER_SUPERSAVE=y or users enable L1.x via sysfs, users may trip over these errors even if L1 Substates haven't been enabled by firmware or the driver. To prevent such errors, disable advertising the L1 PM Substates unless the driver sets "dw_pcie.l1ss_support" to indicate that it knows CLKREQ# is present and any device-specific configuration has been done. Set "dw_pcie.l1ss_support" in tegra194 (if DT includes the "supports-clkreq' property) and qcom (for cfg_2_7_0, cfg_1_9_0, cfg_1_34_0, and cfg_sc8280xp controllers) so they can continue to use L1 Substates. Based on Niklas's patch: https://patch.msgid.link/20251017163252.598812-2-cassel@kernel.org [bhelgaas: drop hiding for endpoints] Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20251118214312.2598220-2-helgaas@kernel.org --- drivers/pci/controller/dwc/pcie-designware.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers/pci/controller/dwc/pcie-designware.c') diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index c644216995f6..6e6a0dac5b53 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -1081,6 +1081,30 @@ void dw_pcie_edma_remove(struct dw_pcie *pci) dw_edma_remove(&pci->edma); } +void dw_pcie_hide_unsupported_l1ss(struct dw_pcie *pci) +{ + u16 l1ss; + u32 l1ss_cap; + + if (pci->l1ss_support) + return; + + l1ss = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_L1SS); + if (!l1ss) + return; + + /* + * Unless the driver claims "l1ss_support", don't advertise L1 PM + * Substates because they require CLKREQ# and possibly other + * device-specific configuration. + */ + l1ss_cap = dw_pcie_readl_dbi(pci, l1ss + PCI_L1SS_CAP); + l1ss_cap &= ~(PCI_L1SS_CAP_PCIPM_L1_1 | PCI_L1SS_CAP_ASPM_L1_1 | + PCI_L1SS_CAP_PCIPM_L1_2 | PCI_L1SS_CAP_ASPM_L1_2 | + PCI_L1SS_CAP_L1_PM_SS); + dw_pcie_writel_dbi(pci, l1ss + PCI_L1SS_CAP, l1ss_cap); +} + void dw_pcie_setup(struct dw_pcie *pci) { u32 val; -- cgit v1.2.3