Re: [PATCH v2] usb: typec: tipd: cd321x: replay the plug on resume

[Sven Peter <sven@kernel.org>]

On 11/12/26 13:28, Jacob Procee wrote:
> On Apple Silicon the Type-C PHY and the dwc3 controller behind a CD321x
> port lose their state during s2idle while the plug stays connected, and
> the CD321x does not raise an interrupt on resume. xhci notices the lost
> state and re-initializes the host controller:
>
>    xhci-hcd xhci-hcd.0.auto: xHC error in resume, USBSTS 0x401, Reinit
>    usb usb1: root hub lost power or was reset
>    usb 1-1: USB disconnect, device number 2
>
> but the PHY is only ever programmed from typec_mux_set(), so a device
> left plugged in (here a FIDO2 security key) never comes back until it is
> unplugged and plugged in again.
>
> Re-initializing only dwc3 after resume does not work: tearing dwc3 down
> also powers off the PHY, and nothing turns it back on, so xhci then
> times out ("Host halt failed, -110", "can't setup: -110").
>
> Instead, make cd321x replay the plug on resume when a partner was
> connected: mark the plug as changed and queue the update work, which
> then goes through the same sequence as a real replug (role none, mux
> safe, mux back to the partner's mode, role back on). Queue the update
> work on system_freezable_wq, from the interrupt path as well, so that no
> update runs before all devices have resumed and the work item is only
> ever queued on one workqueue.
>
> Tested on a 14" MacBook Pro (M1 Pro, j314s) with a backport of this
> change to the Asahi 7.3.3 kernel: a USB-C security key left plugged in
> re-enumerates right after "PM: suspend exit", where it previously stayed
> gone until replugged. Unplugging the device while the system is asleep
> also works: after resume the role goes to none, nothing is brought back
> up, and replugging it later enumerates normally. Booting with the key
> plugged in and replugging it while awake also still work. This mainline
> version was build-tested only (W=1, checkpatch --strict clean).
>
> Fixes: 82432bbfb9e8 ("usb: typec: tipd: Handle mode transitions for CD321x")
> Assisted-by: LLM
> Signed-off-by: Jacob Procee <sn125164@gmail.com>
> ---


Nah, making suspend/resume work isn't the job of the type-c controller.