en Copyright 2015 Java http://kernelsources.org:8080/source/history/linux/Documentation/PCI/controller/pci-controller-drivers.rst#570f7e331f5febb30f1384817463c7e42b65ca7d Merge tag 'pci-v7.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pciPull PCI updates from Bjorn Helgaas: "Resource management: - Add hotplug reservation only once (not at each level of the hierarchy) so bridge windows don't grow more than necessary (Ilpo Järvinen) Driver binding: - Rework device matching so device ID lifetime only needs to cover the probe path since dynamic IDs can be removed at any time (Gary Guo) Error handling: - Update mappings of AER errors to agent & layer and log them for each individual error when multiple errors detected (Lukas Wunner) - Log Error Source only once, not twice in separate messages (Lukas Wunner) - Emit TLP Log only for unmasked errors (Lukas Wunner) - Support Advisory Non-Fatal Errors (Lukas Wunner) - Allow DPC on all Downstream Ports, not just Root Ports, when OS controls AER (Darshit Shah) ASPM: - Program the same ASPM Control values for every function of multi-function devices, as recommended by the PCIe spec (Krishna Chaitanya Chundru) - Avoid L0s for Realtek RTS525A, where it causes an AER interrupt storm (Max Lee) - Avoid ASPM L0s, L1, and L1 PM Substates based on 'aspm-no-l0s', 'aspm-no-l1' [1], and 'aspm-no-l1ss' DT properties (Krishna Chaitanya Chundru) Power management: - Allow D3 for native hotplug-capable Root Ports on non-x86 platforms (we avoid D3 for these ports on x86 because some old platforms didn't validate it) (Manivannan Sadhasivam) - Allow portdrv to claim Ports even if they don't support services (AER, PME, DPC, hotplug, etc) so it can do power management (Brian Norris) Power control: - Add support for PCIe WAKE# interrupt when described via DT (Krishna Chaitanya Chundru) - For the TC9563 PCIe switch: - Take a reference on the I2C adapter to avoid uninterruptible hang when unloading an I2C module while in-use (Johan Hovold) - Update DT binding and driver to restrict Tx Amplitude, DFE and N_FTS to USP, DSP1 and DSP2 (Manivannan Sadhasivam) - Power off only external-facing ports (DSP1, DSP2), leaving USP and DSP3 (aka VDSP) powered up (Manivannan Sadhasivam) - Move integrated MAC Endpoint out of the list of internal ports and configure it separately (Manivannan Sadhasivam) Virtualization: - Add ACS quirk for Pericom PI7C9X2G608 switches (Tim Harvey) - Fix a long-standing bug in the Intel PCH Root Port MPC ACS quirk that didn't update the intended INTEL_MPC_REG_IRBNCE bit because it used a 16-bit config write when a 32-bit write was intended (Mohamad Raizudeen) Procfs: - Avoid spurious runtime PM wakeup on config space accesses that are outside config space and fail before reaching PCI (Krzysztof Wilczyński) - Warn on user-space writes to kernel-exclusive config space regions, as we already do for sysfs (Krzysztof Wilczyński) - Check credentials of opener, not reader, for config space reads, as we already do for sysfs (Krzysztof Wilczyński) Sysfs: - In pci_write_legacy_io(), avoid out-of-bounds reads from the user buffer and fix incorrect ioport write data (1-byte writes on little-endian powerpc, 2- and 4-byte writes on big-endian powerpc) (Krzysztof Wilczyński) - In pci_read_legacy_io(), fix incorrect ioport read data for 2- and 4-byte reads on big-endian powerpc (Krzysztof Wilczyński) - Fix I/O port accessor argument order in Alpha pci_legacy_write() (Krzysztof Wilczyński) - Avoid spurious runtime PM wakeup on config space accesses that are outside config space and fail before reaching PCI (Krzysztof Wilczyński) - Return -EINVAL, not -ENODEV, for mmap of I/O BAR that fails because the arch doesn't support it, as we do for procfs (Krzysztof Wilczyński) - Check for LOCKDOWN_PCI_ACCESS for legacy_io and legacy_mem, as we do for other config space accessors (Krzysztof Wilczyński) Peer-to-peer DMA: - Add Nvidia Vera Rubin to list of platforms that support P2PDMA (Leon Romanovsky) Endpoint framework: - Check doorbell SUCCESS bit in pci_endpoint_test to avoid treating some failures as successes (Niklas Cassel) - Fail doorbell test when the trigger IRQ is missed (Niklas Cassel) New native PCIe controller drivers: - Add DT binding and driver for NVIDIA Tegra264 (Thierry Reding) Native PCIe controllers: - Use common wait time definitions for PCIe link monitoring instead of defining driver-private duplicates (Thierry Reding) Generic host bridge driver: - Fix NULL pointer dereference that caused enumeration failures on 32-bit CAM systems (Steffen Persvold) Amlogic Meson PCIe controller driver: - Correct the PERST# GPIO state so it remains asserted until power and REFCLK become stable to fix enumeration failure (Ronald Claveau) ASPEED PCIe controller driver: - Switch to irq_domain_create_linear() so we can obsolete irq_domain_add_linear() (Jiri Slaby) Cadence PCIe controller driver: - Add MODULE_DEVICE_TABLE to generate module aliases for OF-based module autoloading (Pengpeng Hou) - Add debugfs 'ltssm_status' file for LGA- and HPA-based Cadence controllers (Hans Zhang) - Support up to x4 (not x2) lanes for J200 (Takuma Fujiwara) - Fix host/endpoint dependencies for cadence-plat driver to fix link error when cadence-plat is built-in but the host or endpoint driver is modular (Aksh Garg) Freescale i.MX6 PCIe controller driver: - Add imx6 intr/aer/pme interrupt lines for i.MX95 (Richard Zhu) - Remove PERST# checking from pci_host_common_parse_port() so callers can decide whether to fall back to legacy DT binding with PERST# in the host bridge (Sherry Sun) - Fix build issues when PCI_PWRCTRL_GENERIC or PCI_HOST_COMMON is a module (Arnd Bergmann) - Create pwrctrl devices only once by doing it from imx_pcie_probe() instead of imx_pcie_host_init(), which is used during both probe and resume (Sherry Sun) - Use 'dw_pcie_rp->skip_pwrctrl_off' to avoid powering off devices during suspend to preserve wakeup capability (Sherry Sun) - Add runtime PM support for i.MX95 to allow dynamic power management when the link is idle (Richard Zhu) Intel VMD host bridge driver: - Support device ID 0x28C1 and assume that BIOS has already enumerated the hierarchy below VMD and stored bus range info for OS to use (Nirmal Patel) - Add support for VMCONFIG BUS_RESTRICT_CFG=3, which makes it possible to enumerate downstream devices on Intel Arrow Lake-HX systems and probably others (Ali Alaei) - Pay attention to _OSC negotiation for VMD hierarchy only when running on bare metal, not when running in a VM (Nirmal Patel) - Add Nova Lake (NVL) and Dunlow (DNL) Device IDs (Szymon Durawa) MediaTek PCIe controller driver: - Add support for PCIe controller in EcoNet EN7528 and EN751221 SoCs (Caleb James DeLisle) MediaTek PCIe Gen3 controller driver: - Add mediatek-gen3 'memory-region' for restricted DMA buffer (Chen-Yu Tsai) NVIDIA Tegra264 PCIe controller driver: - Distinguish Tegra264 C0 PCIe controller for internal GPU from C1-C5 controllers so the unit address matches the first 'reg' entry (Thierry Reding) - Add Tegra264 Root Port stanzas to prepare for generic WAKE# handling (Thierry Reding) Qualcomm PCIe controller driver: - Add IPQ9650 compatible with global interrupt (Kathiravan Thirumoorthy) - Add IPQ5210 compatible with IPQ9574 fallback (Varadarajan Narayanan) - Add DT binding and driver support for Hawi SoC (Matthew Leung) - Skip PERST# GPIOs provided by downstream PCIe devices, which should be handled by drivers of those devices (Manivannan Sadhasivam) - Stop advertising Attention Button Present (no Qcom SoCs support Attention Buttons) so pciehp can use Presence Detect Changed events (Qiang Yu) Renesas R-Car PCIe controller driver: - Add rcar-gen4-pci-host optional 'msi-parent' for GIT ITS (Marek Vasut) - When MSI is enabled but iMSI-RX is not used, configure AXIINTC to allow GIT ITS to handle MSI (Marek Vasut) - Refactor GIC600 implementation to make it easier to add platforms that only support 32-bit addressing (Marek Vasut) - Add Renesas R-Car Gen4 S4/V4H/V4M to the list of GIC600 integrations that only support 32-bit addressing (Marek Vasut) Renesas RZ/G3S PCIe controller driver: - Add DT binding and driver support for RZ/V2H(P) SoC, which contains two PCIe controllers, configured either as a single x4 link or two independent x2 link controllers (Lad Prabhakar) SpacemiT K1 PCIe controller driver: - Add missing MODULE_DEVICE_TABLE() to generate module alias info for OF-based module autoloading (Pengpeng Hou) StarFive PCIe controller driver: - Fix resource leaks on error paths in host_init() (Ali Tariq) - Fix runtime PM handling and teardown ordering to avoid register access while power or clocks are disabled (Ali Tariq) - Check for runtime PM resume failure to avoid register access while power or clocks are disabled (Ali Tariq) Synopsys DesignWare PCIe controller driver: - Add LECARC PMU IDs to the DWC RAS/DES VSEC list so it can take advantage of the existing debugfs support for silicon debug, error injection, and event counters (Brett Zhou) - Factor pcie_valid_speed() and pci_bus_speed2lnkctl2() out of bwctrl so they can be shared by the DWC core (Hans Zhang) - Flush MSI writes from endpoint before unmapping the iATU, as we already do for MSI-X writes (Niklas Cassel) - Unmap MSI iATU window before mapping MSI-X window, to avoid a subsequent MSI write using a disabled aperture and losing the interrupt (Niklas Cassel) - Change endpoint .pre_init() and .init() callbacks to return errors and handle them (Marek Vasut) UltraRISC PCIe controller driver: - Add 'core', 'dbi', and 'aux' clocks to DT binding and manage them in the driver (Jia Wang) - Use module_platform_driver() since this may be built as a module, though not removable because IRQs can't be safely disposed (Jia Wang) MicroSemi Switchtec management driver: - Add Microchip PCI1008 device ID and include it in NTB DMA alias quirk (Logan Gunthorpe) Miscellaneous: - Document how to write PCI Host Controller drivers (Manivannan Sadhasivam) - Fix typos in documentation (D'Orus Tsitera) - Use %pe format specifier to print error pointers so we get symbolic errname when available (Krzysztof Wilczyński)"* tag 'pci-v7.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (124 commits) PCI: vmd: Add Nova Lake (NVL) and Dunlow (DNL) Device IDs PCI: tegra264: Add Tegra264 support dt-bindings: PCI: tegra264: Switch to PCIe Root Port bindings dt-bindings: PCI: tegra264: Strictly distinguish C0 from C1-C5 PCI/AER: Support Advisory Non-Fatal Errors PCI: Fix 32-bit config write in Intel PCH Root Port MPC ACS quirk PCI: dwc: Handle return value from endpoint .pre_init callback PCI: dwc: Handle return value from endpoint .init callback PCI: dwc: Add PCI ID for LECARC PCIe PMU PCI/ASPM: Mask ASPM states based on Devicetree properties PCI/ASPM: Disable/restore ASPM on every function for multi-function devices Documentation: PCI: Document how to write PCI Host Controller drivers PCI/ASPM: Use pcie_capability_clear_and_set_word() for ASPM disable/restore PCI: Add support for PCIe WAKE# interrupt PCI: Allow D3 for native hotplug-capable Root Ports on non-x86 platforms dt-bindings: PCI: Correct white-space style PCI/ASPM: Avoid L0s for Realtek RTS525A PCI: ultrarisc: Use module_platform_driver() PCI: ultrarisc: Get and enable DP1000 PCIe controller clocks dt-bindings: PCI: ultrarisc: Add required DP1000 PCIe clocks ... List of files: /linux/Documentation/PCI/controller/pci-controller-drivers.rst Sun, 23 Aug 2026 21:44:10 +0200 Linus Torvalds <torvalds@linux-foundation.org> http://kernelsources.org:8080/source/history/linux/Documentation/PCI/controller/pci-controller-drivers.rst#749fa6a99e73e66b96225868bbf15b66751c06fc Merge branch 'pci/doc'- Document how to write PCI Host Controller drivers (Manivannan Sadhasivam)* pci/doc: Documentation: PCI: Document how to write PCI Host Controller drivers List of files: /linux/Documentation/PCI/controller/pci-controller-drivers.rst Fri, 21 Aug 2026 23:40:33 +0200 Bjorn Helgaas <bhelgaas@google.com> http://kernelsources.org:8080/source/history/linux/Documentation/PCI/controller/pci-controller-drivers.rst#1af156149d9a7de8e6cc44f09f4150cb677bf1bf Documentation: PCI: Document how to write PCI Host Controller driversWriting a PCI Host Controller driver requires bringing up the Root Complexhardware and registering it with the PCI core in a specific sequence. Adda guide describing these steps to help developers write new drivers.It covers the Root Complex topology and enumeration, and walks through thedriver flow, including resource setup, Configuration Space accessors,address translation, interrupt handling, Link training, power management,shutdown and removal, using standard guidelines/best practices.Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>Link: https://patch.msgid.link/20260803-pci-doc-v1-1-2814f8672cad@oss.qualcomm.com List of files: /linux/Documentation/PCI/controller/pci-controller-drivers.rst Mon, 03 Aug 2026 09:25:24 +0200 Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>