Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2021-08-13 23:04:33
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[+cc Ben, Mika] On Thu, Aug 05, 2021 at 09:59:15PM +0530, Amey Narkhede wrote:
quoted hunk ↗ jump to hunk
From: Shanker Donthineni <redacted> 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(). 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 <redacted> Reviewed-by: Alex Williamson <redacted> --- 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 eaddbf701759..dae021322b3f 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);
I *think* the Root Port code farther down in this function is also now
unnecessary:
acpi_pci_bridge_d3(...)
{
...
root = pcie_find_root_port(dev);
adev = ACPI_COMPANION(&root->dev);
if (root == dev) {
/*
* It is possible that the ACPI companion is not yet bound
* for the root port so look it up manually here.
*/
if (!adev && !pci_dev_is_added(root))
adev = acpi_pci_find_companion(&root->dev);
}
Since we're now setting the ACPI_COMPANION for every pci_dev long
before we get here, I think this could now be simplified to something
like this:
acpi_pci_bridge_d3(...)
{
if (!dev->is_hotplug_bridge)
return false;
adev = ACPI_COMPANION(&dev->dev);
if (adev && acpi_device_power_manageable(adev))
return true;
root = pcie_find_root_port(dev);
if (!root)
return false;
adev = ACPI_COMPANION(&root->dev);
if (!adev)
return false;
rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
ACPI_TYPE_INTEGER, &val);
if (rc < 0)
return false;
return val == 1;
}
acpi_pci_bridge_d3() was added by 26ad34d510a8 ("PCI / ACPI: Whitelist
D3 for more PCIe hotplug ports") [1], so I cc'd Mika in case he has
any comment.
quoted hunk ↗ jump to hunk
if (adev && acpi_device_power_manageable(adev))diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 379e85037d9b..15a6975d3757 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c@@ -1789,6 +1789,9 @@ 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);
Is there a reason why you moved pci_set_of_node() from
pci_scan_device() to here? I think it's a good change; I'm just
curious if you tripped over something that required it.
The pci_set_of_node() was added to pci_scan_device() by 98d9f30c820d
("pci/of: Match PCI devices to OF nodes dynamically") [2], so I cc'd
Ben just in case there's some reason he didn't put it in
pci_setup_device() in the first place.
quoted hunk ↗ jump to hunk
pci_dev_assign_slot(dev); /*@@ -1924,6 +1927,7 @@ 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:@@ -2351,10 +2355,7 @@ 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;
[1] https://git.kernel.org/linus/26ad34d510a8 [2] https://git.kernel.org/linus/98d9f30c820d