On 6/24/25 5:24 AM, Rafael J. Wysocki wrote:
On Tue, Jun 24, 2025 at 9:22 AM Lukas Wunner <lukas@xxxxxxxxx> wrote:
[cc += Rafael, Mika]
On Mon, Jun 23, 2025 at 02:13:34PM -0500, Mario Limonciello wrote:
From: Mario Limonciello <mario.limonciello@xxxxxxx>
When a USB4 dock is unplugged the PCIe bridge it's connected to will
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.
It doesn't make sense to runtime resume disconnected devices to D0 and
report the (expected) error, so bail early.
Suggested-by: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx>
---
v4:
* no info message
v3:
* Adjust text and subject
* Add an info message instead
v2:
* Use pci_dev_is_disconnected()
v1: https://lore.kernel.org/linux-usb/20250609020223.269407-1-superm1@xxxxxxxxxx/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 9e42090fb1089..160a9a482c732 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;
Why not PCI_UNKNOWN?
It was following what other situations of failure did:
* existing error in pci_power_up()
* error in pci_update_current_state()
* error in pci_set_low_power_state()
I view all of these cases as unrecoverable failures.
So perhaps if changing this one to PCI_UNKNOWN those three should those
also be PCI_UNKNOWN?
Bjorn, Lukas, thoughts?
+ 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
