Re: Unplugging USB-C charger cable causes `ucsi_acpi USBC000:00: ucsi_handle_connector_change: ACK failed (-110)`

[Paul Menzel]

Dear Heikki,


Am 22.11.23 um 09:56 schrieb Heikki Krogerus:
> On Tue, Nov 21, 2023 at 03:25:59PM +0100, Paul Menzel wrote:

> > Am 21.11.23 um 15:08 schrieb Heikki Krogerus:
> > > On Tue, Nov 21, 2023 at 12:50:43PM +0100, Paul Menzel wrote:
> >
> > > > On the Dell XPS 13, BIOS 2.21.0 06/02/2022, with Debian sid/unstable and
> > > > Linux 6.5.10, when unplugging the (Dell) USB Type-C charger cable, Linux
> > > > logs the error below:
> > > >
> > > >       ucsi_acpi USBC000:00: ucsi_handle_connector_change: ACK failed (-110)
> > > >
> > > > As this is logged with level error, can this be somehow fixed?
> > > >
> > > >       drivers/usb/typec/ucsi/ucsi.c: dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);
> > > >
> > > > Please find the output of `dmesg` attached.
> > >
> > > Thanks. The firmware not reacting to the ACK command is weird, but I'm
> > > not sure if it's critical. Does the interface continue working after
> > > that? Do you see the partner devices appearing under /sys/class/typec/
> > > when you plug them, and disappearing when you unplug them?
> >
> > ```
> > $ LANG= grep . /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000\:001/*
> > /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000:001/current_max:0
> > /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000:001/current_now:0

[…]

> > ```
> >
> > Now I unplugged the device, and the error is *not* logged. (I had a USB
> > Type-C port replicator plugged in during the day before.)
> >
> > The directory is still there:
> >
> > ```
> > $ LANG= grep . /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000\:001/*
> > /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000:001/current_max:0
> > /sys/class/typec/port0/device/power_supply/ucsi-source-psy-USBC000:001/current_now:0

[…]

> > ```
> >
> > I guess, that is the wrong directory I look at though?
> >
> > (I am going to monitor the logs over the next days.)
>
> Just list what you have in /sys/class/typec/ before and after plugging
> a device to the port:
>
>          ls /sys/class/typec/

Sorry, here you go:

With charger:

    $ ls /sys/class/typec/
    port0  port0-partner

After unplugging the charger:

    $ LANG= ls /sys/class/typec/
    port0

By the way, Linux logs the ucsi_handle_connector_change line around five 
second after unplugging the USB Type-C charger cable.


Kind regards,

Paul


PS: In the logs since October 30th, I see the three distinct lines below:

1.  ucsi_acpi USBC000:00: failed to re-enable notifications (-110)
2.  ucsi_acpi USBC000:00: GET_CONNECTOR_STATUS failed (-110)
3.  ucsi_acpi USBC000:00: ucsi_handle_connector_change: ACK failed (-110)

Is it documented somewhere what -100 means?