[PATCH v10 6/8] PCI: Setup ACPI fwnode early and at the same time with OF

From: Amey Narkhede
Date: Fri Jul 09 2021 - 08:39:10 EST


From: Shanker Donthineni <sdonthineni@xxxxxxxxxx>

The pci_dev objects are created through two mechanisms 1) during PCI
bus scan and 2) from I/O Virtualization. The fwnode in pci_dev object
is being set at different places depends on the type of firmware used,
device creation mechanism, and acpi_pci_bridge_d3() WAR.

The software features which have a dependency on ACPI fwnode properties
and need to be handled before device_add() will not work. One use case,
the software has to check the existence of _RST method to support ACPI
based reset method.

This patch does the two changes in order to provide fwnode consistently.
- Set ACPI and OF fwnodes from pci_setup_device().
- Remove pci_set_acpi_fwnode() in acpi_pci_bridge_d3().

After this patch, ACPI/OF firmware properties are visible at the same
time during the early stage of pci_dev setup. And also call sites should
be able to use firmware agnostic functions device_property_xxx() for the
early PCI quirks in the future.

Signed-off-by: Shanker Donthineni <sdonthineni@xxxxxxxxxx>
---
drivers/pci/pci-acpi.c | 1 -
drivers/pci/probe.c | 7 ++++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index eaddbf701..dae021322 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
return false;

/* Assume D3 support if the bridge is power-manageable by ACPI. */
- pci_set_acpi_fwnode(dev);
adev = ACPI_COMPANION(&dev->dev);

if (adev && acpi_device_power_manageable(adev))
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c272e23db..c911d6a5c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1790,6 +1790,9 @@ int pci_setup_device(struct pci_dev *dev)
dev->error_state = pci_channel_io_normal;
set_pcie_port_type(dev);

+ pci_set_of_node(dev);
+ pci_set_acpi_fwnode(dev);
+
pci_dev_assign_slot(dev);

/*
@@ -1925,6 +1928,7 @@ int pci_setup_device(struct pci_dev *dev)
default: /* unknown header */
pci_err(dev, "unknown header type %02x, ignoring device\n",
dev->hdr_type);
+ pci_release_of_node(dev);
return -EIO;

bad:
@@ -2352,10 +2356,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
dev->vendor = l & 0xffff;
dev->device = (l >> 16) & 0xffff;

- pci_set_of_node(dev);
-
if (pci_setup_device(dev)) {
- pci_release_of_node(dev);
pci_bus_put(dev->bus);
kfree(dev);
return NULL;
--
2.32.0