On Mon, Sep 18, 2023 at 08:30:41AM +0300, Mika Westerberg wrote:
> Mark Blakeney reported that when suspending system with a Thunderbolt
> dock connected and then unplugging the dock before resume (which is
> pretty normal flow with laptops), resuming takes long time.
>
> What happens is that the PCIe link from the root port to the PCIe switch
> inside the Thunderbolt device does not train (as expected, the link is
> upplugged):
>
> [ 34.903158] pcieport 0000:00:07.2: restoring config space at offset 0x24 (was 0x3bf12001, writing 0x3bf12001)
> [ 34.903231] pcieport 0000:00:07.0: waiting 100 ms for downstream link
> [ 36.140616] pcieport 0000:01:00.0: not ready 1023ms after resume; giving up
>
> However, at this point we still try the resume the devices below that
> unplugged link:
>
> [ 36.140741] pcieport 0000:01:00.0: Unable to change power state from D3cold to D0, device inaccessible
> ...
> [ 36.142235] pcieport 0000:01:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
> ...
> [ 36.144702] pcieport 0000:02:02.0: waiting 100 ms for downstream link, after activation
>
> And this is the link from PCIe switch downstream port to the xHCI on the
> dock:
>
> [ 38.380618] xhci_hcd 0000:03:00.0: not ready 1023ms after resume; waiting
> [ 39.420587] xhci_hcd 0000:03:00.0: not ready 2047ms after resume; waiting
> [ 41.527250] xhci_hcd 0000:03:00.0: not ready 4095ms after resume; waiting
> [ 45.793957] xhci_hcd 0000:03:00.0: not ready 8191ms after resume; waiting
> [ 54.113950] xhci_hcd 0000:03:00.0: not ready 16383ms after resume; waiting
> [ 71.180576] xhci_hcd 0000:03:00.0: not ready 32767ms after resume; waiting
> ...
> [ 105.313963] xhci_hcd 0000:03:00.0: not ready 65535ms after resume; giving up
> [ 105.314037] xhci_hcd 0000:03:00.0: Unable to change power state from D3cold to D0, device inaccessible
> [ 105.315640] xhci_hcd 0000:03:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x1ff)
> ...
>
> This ends up slowing down the resume time considerably. For this reason
> mark these devices as disconnected if the link above them did not train
> properly.
>
> Fixes: e8b908146d44 ("PCI/PM: Increase wait time after resume")
> Reported-by: Mark Blakeney <mark.blakeney@xxxxxxxxxxxxxxxxxx>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217915
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx>
