[PATCH 1/4] PCI: Don't show errors on inaccessible PCI devices

[PATCH 1/4] PCI: Don't show errors on inaccessible PCI devices

[Mario Limonciello]

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`.

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 error state and skip the messaging.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/pci/pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9448d55113bd..7b0b4087da4d3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1376,8 +1376,9 @@ int pci_power_up(struct pci_dev *dev)
 
 	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",
-			pci_power_name(dev->current_state));
+		if (dev->error_state != pci_channel_io_perm_failure)
+			pci_err(dev, "Unable to change power state from %s to D0, device inaccessible\n",
+				pci_power_name(dev->current_state));
 		dev->current_state = PCI_D3cold;
 		return -EIO;
 	}
-- 
2.43.0

[PATCH 2/4] PCI: Fix runtime PM usage count underflow

[Mario Limonciello]

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`.

When PCI core gets to the point that the device is removed using
pci_device_remove() the runtime count has already been decremented and
so calling pm_runtime_put_sync() will cause an underflow.

Detect the device is in the error state and skip the call for this cleanup
path.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/pci/pci-driver.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 9f6e145d93d62..ab4cfdfc8fbc0 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -479,7 +479,8 @@ static void pci_device_remove(struct device *dev)
 	pci_iov_remove(pci_dev);
 
 	/* Undo the runtime PM settings in local_pci_probe() */
-	pm_runtime_put_sync(dev);
+	if (pci_dev->error_state != pci_channel_io_perm_failure)
+		pm_runtime_put_sync(dev);
 
 	/*
 	 * If the device is still on, set the power state as "unknown",
-- 
2.43.0