[PATCH v2 1/2] PCI: Don't show errors on inaccessible PCI devices

[Mario Limonciello <superm1@kernel.org>]

From: Mario Limonciello <mario.limonciello@amd.com>

When a USB4 dock is unplugged the PCIe bridge it's connected to will
remove issue a "Link Down" and "Card not detected event". The PCI core
will treat this as a surprise hotplug event and unconfigure all downstream
devices. This involves setting the device error state to
`pci_channel_io_perm_failure` which pci_dev_is_disconnected() will check.

As the device is already gone and the PCI core is cleaning up there isn't
really any reason to show error messages to the user about failing to
change power states. Detect the device is marked disconnected and skip the
messaging.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Use pci_dev_is_disconnected()
v1: https://lore.kernel.org/linux-usb/20250609020223.269407-1-superm1@kernel.org/T/#mf95c947990d016fbfccfd11afe60b8ae08aafa0b
---
 drivers/pci/pci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9448d55113bd..3dd44d1ad829b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1374,6 +1374,11 @@ int pci_power_up(struct pci_dev *dev)
 		return -EIO;
 	}
 
+	if (pci_dev_is_disconnected(dev)) {
+		dev->current_state = PCI_D3cold;
+		return -EIO;
+	}
+
 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
 	if (PCI_POSSIBLE_ERROR(pmcsr)) {
 		pci_err(dev, "Unable to change power state from %s to D0, device inaccessible\n",
-- 
2.43.0