From 3a59c3b772e5dc0cedecce8e7fbf7c2d6245b643 Mon Sep 17 00:00:00 2001 From: Chen Pei Date: Tue, 26 May 2026 10:51:17 +0800 Subject: [PATCH] ACPI: PCI: Clear _DEP dependencies after PCI root bridge attach PCI root bridges enumerated by acpi_pci_root_add() can be the _DEP supplier for other ACPI consumers, most notably ACPI0017 CXL root devices whose probe path depends on acpi_pci_find_root() succeeding. Once the root bus has been added, those consumers can safely be enumerated, so notify them by clearing the dependency. Call acpi_dev_clear_dependencies() at the end of acpi_pci_root_add(), after pci_bus_add_devices(), following the same pattern used by other ACPI suppliers such as the EC (drivers/acpi/ec.c) and the ACPI PCI Link device (drivers/acpi/pci_link.c). The clear is intentionally done only on the success path; on the error paths the supplier did not attach and consumers must keep dep_unmet set. This is a prerequisite for honoring _DEP on ACPI0016 host bridges, which matters on architectures where the probe order of acpi_pci_root relative to cxl_acpi is not guaranteed (e.g. RISC-V). Signed-off-by: Chen Pei Suggested-by: Dan Williams (nvidia) Tested-by: Alison Schofield Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260526025118.38935-2-cp0613@linux.alibaba.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/pci_root.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index a0ba64e45e8a..4c06c3ffd0cb 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -755,6 +755,10 @@ static int acpi_pci_root_add(struct acpi_device *device, pci_lock_rescan_remove(); pci_bus_add_devices(root->bus); pci_unlock_rescan_remove(); + + /* Clear _DEP dependencies to allow consumers to enumerate */ + acpi_dev_clear_dependencies(device); + return 1; remove_dmar: