PCI: Restrict device disabled status check to DT

Commit 6fffbc7ae137 ("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: 6fffbc7ae137 ("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: Donald Hunter <donald.hunter@gmail.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Donald Hunter <donald.hunter@gmail.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Cc: Liu Peibao <liupeibao@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 196834ed44fe84595a696159dd42deb24ec42b71..4c2ef2e28fb5e9030a0e8ed41d2bcd883a00c16c 100644 (file)
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -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)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d2c08670a20ed77823e65a748365d15f0a0bf875..2b48a0aa8008e5547ee258ad83759fb3177e2dd4 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -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) { }

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index a3f68b6ba6ac2db4500e5f5f416b972e479746d9..f96fa83f2627386677a4efcf10c7a971873dbd99 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -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);