[PATCH v7 08/17] ACPI: pci_link: Clear the dependencies after probe

Sunil V L sunilvl at ventanamicro.com
Mon Jul 29 07:22:30 PDT 2024


RISC-V platforms need to use dependencies between PCI host bridge, Link
devices and the interrupt controllers to ensure probe order. The
dependency is like below.

Interrupt controller <-- Link Device <-- PCI Host bridge.

If there is no dependency added between Link device and PCI Host Bridge,
then the PCI end points can get probed prior to link device, unable to
get mapping for INTx.

So, add the link device's HID to dependency honor list and also clear it
after its probe.

Signed-off-by: Sunil V L <sunilvl at ventanamicro.com>
---
 drivers/acpi/pci_link.c | 2 ++
 drivers/acpi/scan.c     | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index aa1038b8aec4..b727db968f33 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -748,6 +748,8 @@ static int acpi_pci_link_add(struct acpi_device *device,
 	if (result)
 		kfree(link);
 
+	acpi_dev_clear_dependencies(device);
+
 	return result < 0 ? result : 1;
 }
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 28a221f956d7..753539a1f26b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -863,6 +863,7 @@ static const char * const acpi_honor_dep_ids[] = {
 	"INTC10CF", /* IVSC (MTL) driver must be loaded to allow i2c access to camera sensors */
 	"RSCV0001", /* RISC-V PLIC */
 	"RSCV0002", /* RISC-V APLIC */
+	"PNP0C0F",  /* PCI Link Device */
 	NULL
 };
 
-- 
2.43.0




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