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| author | Chen Pei <cp0613@linux.alibaba.com> | 2026-05-26 05:51:17 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-06-01 20:25:37 +0300 |
| commit | 3a59c3b772e5dc0cedecce8e7fbf7c2d6245b643 (patch) | |
| tree | 0bb3fef1145f912f0e22c76cbbaf72e147b8d62f | |
| parent | e43ffb69e0438cddd72aaa30898b4dc446f664f8 (diff) | |
| download | linux-3a59c3b772e5dc0cedecce8e7fbf7c2d6245b643.tar.xz | |
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 <cp0613@linux.alibaba.com>
Suggested-by: Dan Williams (nvidia) <djbw@kernel.org>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260526025118.38935-2-cp0613@linux.alibaba.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/pci_root.c | 4 |
1 files changed, 4 insertions, 0 deletions
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: |