PCI: Don't attempt config access to disconnected devices

[mirror_ubuntu-bionic-kernel.git] / drivers / pci / access.c

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index c70e3113df7aa5ac582669364332524c60d34770..1c8051003e676dd48124b02f40c8e32a67f485b8 100644 (file)
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -893,12 +893,20 @@ EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
 
 int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
 {
+       if (pci_dev_is_disconnected(dev)) {
+               *val = ~0;
+               return -ENODEV;
+       }
        return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_read_config_byte);
 
 int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
 {
+       if (pci_dev_is_disconnected(dev)) {
+               *val = ~0;
+               return -ENODEV;
+       }
        return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_read_config_word);
@@ -906,18 +914,26 @@ EXPORT_SYMBOL(pci_read_config_word);
 int pci_read_config_dword(const struct pci_dev *dev, int where,
                                        u32 *val)
 {
+       if (pci_dev_is_disconnected(dev)) {
+               *val = ~0;
+               return -ENODEV;
+       }
        return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_read_config_dword);
 
 int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
 {
+       if (pci_dev_is_disconnected(dev))
+               return -ENODEV;
        return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_write_config_byte);
 
 int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
 {
+       if (pci_dev_is_disconnected(dev))
+               return -ENODEV;
        return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_write_config_word);
@@ -925,6 +941,8 @@ EXPORT_SYMBOL(pci_write_config_word);
 int pci_write_config_dword(const struct pci_dev *dev, int where,
                                         u32 val)
 {
+       if (pci_dev_is_disconnected(dev))
+               return -ENODEV;
        return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
 }
 EXPORT_SYMBOL(pci_write_config_dword);