From: Chen Pei Date: Tue, 26 May 2026 02:51:18 +0000 (+0800) Subject: ACPI: scan: Honor _DEP for ACPI0016 PCI/CXL host bridge X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=bf5418a5fe63f35da35941ae896d5df121d95ffc;p=thirdparty%2Flinux.git ACPI: scan: Honor _DEP for ACPI0016 PCI/CXL host bridge CXL root devices (ACPI0017) declare _DEP on their parent ACPI0016 PCI/CXL host bridge so that cxl_acpi probes only after acpi_pci_root has attached the PCI root and registered it for acpi_pci_find_root(). However, acpi_dev_ready_for_enumeration() only consults dep_unmet when the supplier's HID is on acpi_honor_dep_ids[]; otherwise the dependency is silently ignored. Without honoring the dependency, cxl_acpi can probe before the PCI root is ready. The resulting CXL topology is broken: decoder targets read as 0 and no port/endpoint devices appear under /sys/bus/cxl/devices/. Add ACPI0016 to acpi_honor_dep_ids[] so the _DEP declared by ACPI0017 is enforced. This relies on the preceding patch ("ACPI: PCI: clear _DEP dependencies after PCI root bridge attach"), which releases the dependency once the PCI root is fully enumerated; the two patches must be applied together. Signed-off-by: Chen Pei Tested-by: Alison Schofield Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260526025118.38935-3-cp0613@linux.alibaba.com Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 530547cda8b28..5f20e7748f364 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -866,6 +866,7 @@ static const char * const acpi_honor_dep_ids[] = { "RSCV0005", /* RISC-V SBI MPXY MBOX */ "RSCV0006", /* RISC-V RPMI SYSMSI */ "PNP0C0F", /* PCI Link Device */ + "ACPI0016", /* CXL/PCIe host bridge: CXL root (ACPI0017) depends on PCI root attach */ NULL };