On Tue, Jun 24, 2025 at 5:08 PM Mario Limonciello <superm1@xxxxxxxxxx> wrote: > > 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? Note that pci_device_remove() sets power_state to PCI_UNKNOWN, but only if the old value is PCI_D0, so it would be good to make all of that consistent at one point. Anyway, feel free to add Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx> to this patch. Thanks!
