Re: [PATCH] usb: typec: ucsi: cancel pending work on system suspend

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Fri, Jul 03, 2026 at 01:07:37PM +0200, Paul Menzel wrote:
> On a Dell XPS 13 9360 (BIOS 2.21.0), entering system suspend (deep/S3)
> races a pending UCSI connector-change worker against the ACPI EC teardown.
> The worker evaluates the UCSI _DSM (GET_CONNECTOR_STATUS), whose AML
> accesses the Embedded Controller. By that point the ACPI EC has already
> been stopped for suspend, so the EC address space handler rejects the
> access with AE_BAD_PARAMETER, aborting the AML and failing the connector
> query:
> 
>     [22314.689495] ACPI: EC: interrupt blocked
>     [22314.711981] ACPI: PM: Preparing to enter system sleep state S3
>     [22314.743260] ACPI: EC: event blocked
>     [22314.743265] ACPI: EC: EC stopped
>     [22314.743267] ACPI: PM: Saving platform NVS memory
>     [22314.744241] ACPI Error: AE_BAD_PARAMETER, Returned by Handler for [EmbeddedControl] (20260408/evregion-303)
>     [22314.744432] ACPI Error: Aborting method \_SB.PCI0.LPCB.ECDV.ECW1 due to previous error (AE_BAD_PARAMETER) (20260408/psparse-543)
>     [22314.744673] ACPI Error: Aborting method \ECWB due to previous error (AE_BAD_PARAMETER) (20260408/psparse-543)
>     [22314.745201] ACPI Error: Aborting method \_SB.UBTC._DSM due to previous error (AE_BAD_PARAMETER) (20260408/psparse-543)
>     [22314.745394] ACPI: \_SB_.UBTC: failed to evaluate _DSM c298836f-a47c-e411-ad36-631042b5008f rev:1 func:1 (0x1001)
>     [22314.745414] ucsi_acpi USBC000:00: ucsi_acpi_dsm: failed to evaluate _DSM 1
>     [22314.745424] ucsi_acpi USBC000:00: ucsi_handle_connector_change: GET_CONNECTOR_STATUS failed (-5)
> 
> ucsi_acpi implements a resume callback but no suspend callback, so nothing
> cancels the connector-change work before the firmware/EC is torn down.
> 
> Add a `ucsi_suspend()` core helper that cancels the pending init and
> connector-change work, and wire it into ucsi_acpi's PM ops. The connector
> state is re-read on resume by `ucsi_resume()`, so cancelling the work loses
> nothing.
> 
> Fixes: 4e3a50293c2b ("usb: typec: ucsi: acpi: Implement resume callback")
> Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
> Assisted-by: Claude Opus 4.8

No Cc stable? Otherwise this is okay by me:

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Thanks,

> ---
>  drivers/usb/typec/ucsi/ucsi.c      | 20 ++++++++++++++++++++
>  drivers/usb/typec/ucsi/ucsi.h      |  1 +
>  drivers/usb/typec/ucsi/ucsi_acpi.c | 10 +++++++++-
>  3 files changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index 92166a3725b16..6a6723e8fb127 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -2017,6 +2017,26 @@ static void ucsi_resume_work(struct work_struct *work)
>  	}
>  }
>  
> +int ucsi_suspend(struct ucsi *ucsi)
> +{
> +	int i;
> +
> +	/*
> +	 * Cancel pending work so it cannot access the firmware after the ACPI
> +	 * EC is stopped for suspend; state is re-read on resume.
> +	 */
> +	cancel_delayed_work_sync(&ucsi->work);
> +
> +	if (!ucsi->connector)
> +		return 0;
> +
> +	for (i = 0; i < ucsi->cap.num_connectors; i++)
> +		cancel_work_sync(&ucsi->connector[i].work);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ucsi_suspend);
> +
>  int ucsi_resume(struct ucsi *ucsi)
>  {
>  	if (ucsi->connector)
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index 325ed1e5ca804..6e1608d88ec3d 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -582,6 +582,7 @@ int ucsi_write_message_out_command(struct ucsi *ucsi, u64 command,
>  				   void *msg_out, size_t msg_out_size);
>  
>  void ucsi_altmode_update_active(struct ucsi_connector *con);
> +int ucsi_suspend(struct ucsi *ucsi);
>  int ucsi_resume(struct ucsi *ucsi);
>  
>  void ucsi_notify_common(struct ucsi *ucsi, u32 cci);
> diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
> index 60b12961e1a47..18286d3e9cc59 100644
> --- a/drivers/usb/typec/ucsi/ucsi_acpi.c
> +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
> @@ -263,6 +263,13 @@ static void ucsi_acpi_remove(struct platform_device *pdev)
>  				   ucsi_acpi_notify);
>  }
>  
> +static int ucsi_acpi_suspend(struct device *dev)
> +{
> +	struct ucsi_acpi *ua = dev_get_drvdata(dev);
> +
> +	return ucsi_suspend(ua->ucsi);
> +}
> +
>  static int ucsi_acpi_resume(struct device *dev)
>  {
>  	struct ucsi_acpi *ua = dev_get_drvdata(dev);
> @@ -270,7 +277,8 @@ static int ucsi_acpi_resume(struct device *dev)
>  	return ucsi_resume(ua->ucsi);
>  }
>  
> -static DEFINE_SIMPLE_DEV_PM_OPS(ucsi_acpi_pm_ops, NULL, ucsi_acpi_resume);
> +static DEFINE_SIMPLE_DEV_PM_OPS(ucsi_acpi_pm_ops, ucsi_acpi_suspend,
> +				ucsi_acpi_resume);
>  
>  static const struct acpi_device_id ucsi_acpi_match[] = {
>  	{ "PNP0CA0", 0 },
> -- 
> 2.54.0

-- 
heikki