Commit 0d21e71a authored by Rob Herring's avatar Rob Herring Committed by Bjorn Helgaas
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PCI: Restrict device disabled status check to DT 

Commit 6fffbc7a ("PCI: Honor firmware's device disabled status")
checked the firmware device status for both DT and ACPI devices. That
caused a regression in some ACPI systems. The exact reason isn't clear.
It's possibly a firmware bug. For now, at least, refactor the check to
be for DT based systems only.

Note that the original implementation leaked a refcount which is now
correctly handled.

[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable bus, _STA
must return with bit[0] ("device is present") set]

Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
Fixes: 6fffbc7a ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/r/20230419193513.708818-1-robh@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317


Reported-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Reported-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Tested-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Cc: Liu Peibao <liupeibao@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>
parent fe15c26e

drivers/pci/of.c

+24 −6
Original line number Diff line number Diff line
@@ -16,14 +16,32 @@ 
#include "pci.h"



#ifdef CONFIG_PCI

void pci_set_of_node(struct pci_dev *dev)

/**

 * pci_set_of_node - Find and set device's DT device_node

 * @dev: the PCI device structure to fill

 *

 * Returns 0 on success with of_node set or when no device is described in the

 * DT. Returns -ENODEV if the device is present, but disabled in the DT.

 */

int pci_set_of_node(struct pci_dev *dev)

{

	struct device_node *node;



	if (!dev->bus->dev.of_node)

		return;

	dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,

						    dev->devfn);

	if (dev->dev.of_node)

		dev->dev.fwnode = &dev->dev.of_node->fwnode;

		return 0;



	node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);

	if (!node)

		return 0;



	if (!of_device_is_available(node)) {

		of_node_put(node);

		return -ENODEV;

	}



	dev->dev.of_node = node;

	dev->dev.fwnode = &node->fwnode;

	return 0;

}



void pci_release_of_node(struct pci_dev *dev)

drivers/pci/pci.h

+2 −2
Original line number Diff line number Diff line
@@ -624,7 +624,7 @@ int of_pci_get_max_link_speed(struct device_node *node); 
u32 of_pci_get_slot_power_limit(struct device_node *node,

				u8 *slot_power_limit_value,

				u8 *slot_power_limit_scale);

void pci_set_of_node(struct pci_dev *dev);

int pci_set_of_node(struct pci_dev *dev);

void pci_release_of_node(struct pci_dev *dev);

void pci_set_bus_of_node(struct pci_bus *bus);

void pci_release_bus_of_node(struct pci_bus *bus);
@@ -662,7 +662,7 @@ of_pci_get_slot_power_limit(struct device_node *node, 
	return 0;

}



static inline void pci_set_of_node(struct pci_dev *dev) { }

static inline int pci_set_of_node(struct pci_dev *dev) { return 0; }

static inline void pci_release_of_node(struct pci_dev *dev) { }

static inline void pci_set_bus_of_node(struct pci_bus *bus) { }

static inline void pci_release_bus_of_node(struct pci_bus *bus) { }

drivers/pci/probe.c

+4 −4
Original line number Diff line number Diff line
@@ -1826,7 +1826,7 @@ int pci_setup_device(struct pci_dev *dev) 
	u32 class;

	u16 cmd;

	u8 hdr_type;

	int pos = 0;

	int err, pos = 0;

	struct pci_bus_region region;

	struct resource *res;
@@ -1840,10 +1840,10 @@ 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);

	err = pci_set_of_node(dev);

	if (err)

		return err;

	pci_set_acpi_fwnode(dev);

	if (dev->dev.fwnode && !fwnode_device_is_available(dev->dev.fwnode))

		return -ENODEV;



	pci_dev_assign_slot(dev);