[v1] usb: typec: ucsi: allow retries of ucsi_resume_work

[PATCH v1] usb: typec: ucsi: allow retries of ucsi_resume_work

Posted by Jameson Thies 1 month, 1 week ago

On resume, the UCSI driver will re-enable notifications by sending
SET_NOTIFICATION_ENABLE. The LPM/PPM may be busy during system
resume causing SET_NOTIFICATION_ENABLE to fail and preventing the UCSI
driver from receiving connection status changes.

Change resume work to a delayed workqueue to allow retries on failed
SET_NOTIFICATION_ENABLED commands. Additionally, cancel resume work
on suspend to prevent pending resume commands from impacting suspend.

Signed-off-by: Jameson Thies <jthies@google.com>
---
 drivers/usb/typec/ucsi/ucsi.c | 18 +++++++++++++-----
 drivers/usb/typec/ucsi/ucsi.h |  3 ++-
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index bef3f9b71d71..5c67f0990dd3 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -2158,7 +2158,7 @@ static int ucsi_init(struct ucsi *ucsi)
 
 static void ucsi_resume_work(struct work_struct *work)
 {
-	struct ucsi *ucsi = container_of(work, struct ucsi, resume_work);
+	struct ucsi *ucsi = container_of(to_delayed_work(work), struct ucsi, resume_work);
 	struct ucsi_connector *con;
 	u64 command;
 	int ret;
@@ -2167,6 +2167,11 @@ static void ucsi_resume_work(struct work_struct *work)
 	command = UCSI_SET_NOTIFICATION_ENABLE | ucsi->ntfy;
 	ret = ucsi_send_command(ucsi, command, NULL, 0);
 	if (ret < 0) {
+		if (++ucsi->resume_retries < 5) {
+			queue_delayed_work(system_long_wq, &ucsi->resume_work,
+					   msecs_to_jiffies(500));
+			return;
+		}
 		dev_err(ucsi->dev, "failed to re-enable notifications (%d)\n", ret);
 		return;
 	}
@@ -2187,6 +2192,7 @@ int ucsi_suspend(struct ucsi *ucsi)
 	 * EC is stopped for suspend; state is re-read on resume.
 	 */
 	cancel_delayed_work_sync(&ucsi->work);
+	cancel_delayed_work_sync(&ucsi->resume_work);
 
 	if (!ucsi->connector)
 		return 0;
@@ -2200,8 +2206,10 @@ EXPORT_SYMBOL_GPL(ucsi_suspend);
 
 int ucsi_resume(struct ucsi *ucsi)
 {
-	if (ucsi->connector)
-		queue_work(system_long_wq, &ucsi->resume_work);
+	if (ucsi->connector) {
+		ucsi->resume_retries = 0;
+		queue_delayed_work(system_long_wq, &ucsi->resume_work, 0);
+	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ucsi_resume);
@@ -2299,7 +2307,7 @@ struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops)
 	if (!ucsi)
 		return ERR_PTR(-ENOMEM);
 
-	INIT_WORK(&ucsi->resume_work, ucsi_resume_work);
+	INIT_DELAYED_WORK(&ucsi->resume_work, ucsi_resume_work);
 	INIT_DELAYED_WORK(&ucsi->work, ucsi_init_work);
 	mutex_init(&ucsi->ppm_lock);
 	init_completion(&ucsi->complete);
@@ -2365,7 +2373,7 @@ void ucsi_unregister(struct ucsi *ucsi)
 
 	/* Make sure that we are not in the middle of driver initialization */
 	cancel_delayed_work_sync(&ucsi->work);
-	cancel_work_sync(&ucsi->resume_work);
+	cancel_delayed_work_sync(&ucsi->resume_work);
 
 	ucsi_debugfs_unregister(ucsi);
 
diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index dc594388dcd0..1996f04ed5e6 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -484,7 +484,8 @@ struct ucsi {
 	struct ucsi_connector *connector;
 	struct ucsi_debugfs_entry *debugfs;
 
-	struct work_struct resume_work;
+	struct delayed_work resume_work;
+	int resume_retries;
 	struct delayed_work work;
 	int work_count;
 #define UCSI_ROLE_SWITCH_RETRY_PER_HZ	10

base-commit: bdab5605259ba5d6ff927c1a85cc83eb3ecfdacc
-- 
2.55.0.737.g08866a6d13-goog

Re: [PATCH v1] usb: typec: ucsi: allow retries of ucsi_resume_work

Posted by Marco Crivellari 1 month ago

Hi,

>+		if (++ucsi->resume_retries < 5) {
>+			queue_delayed_work(system_long_wq, &ucsi->resume_work,
>+					   msecs_to_jiffies(500));
>+			return;
>+		}

Just one thing about this (same applies to the other queue_delayed_work() calls).

queue_delayed_work() calls:

queue_delayed_work_on(WORK_CPU_UNBOUND,...)
    __queue_delayed_work(cpu, wq, dwork, delay)
        __queue_delayed_work(cpu,...)

That perform this check:

	if (likely(cpu == WORK_CPU_UNBOUND))
		add_timer_global(timer);
	else
		...

It means the timer used is global / unbound: when it fires it will enqueue
the work on the CPU where the timer is executed. The workqueue you're
using is per-CPU.

I guess locality is not needed for correctness here, because of that, so
you can replace that workqueue with system_dfl_long_wq. This is the
unbound version.

system_long_wq is scheduled for removal.

Thanks,

--

Marco Crivellari

SUSE Labs

Re: [PATCH v1] usb: typec: ucsi: allow retries of ucsi_resume_work

Posted by Jameson Thies 3 weeks, 3 days ago

Hi Marco, thank you for taking a look at this patch.

> system_long_wq is scheduled for removal.

I'll post a v2 switching to system_dfl_long_wq.

- Jameson

Re: [PATCH v1] usb: typec: ucsi: allow retries of ucsi_resume_work

Posted by Heikki Krogerus 1 month ago

On Tue, Aug 18, 2026 at 08:57:17PM +0000, Jameson Thies wrote:
> On resume, the UCSI driver will re-enable notifications by sending
> SET_NOTIFICATION_ENABLE. The LPM/PPM may be busy during system
> resume causing SET_NOTIFICATION_ENABLE to fail and preventing the UCSI
> driver from receiving connection status changes.
> 
> Change resume work to a delayed workqueue to allow retries on failed
> SET_NOTIFICATION_ENABLED commands. Additionally, cancel resume work
> on suspend to prevent pending resume commands from impacting suspend.
> 
> Signed-off-by: Jameson Thies <jthies@google.com>

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

> ---
>  drivers/usb/typec/ucsi/ucsi.c | 18 +++++++++++++-----
>  drivers/usb/typec/ucsi/ucsi.h |  3 ++-
>  2 files changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index bef3f9b71d71..5c67f0990dd3 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -2158,7 +2158,7 @@ static int ucsi_init(struct ucsi *ucsi)
>  
>  static void ucsi_resume_work(struct work_struct *work)
>  {
> -	struct ucsi *ucsi = container_of(work, struct ucsi, resume_work);
> +	struct ucsi *ucsi = container_of(to_delayed_work(work), struct ucsi, resume_work);
>  	struct ucsi_connector *con;
>  	u64 command;
>  	int ret;
> @@ -2167,6 +2167,11 @@ static void ucsi_resume_work(struct work_struct *work)
>  	command = UCSI_SET_NOTIFICATION_ENABLE | ucsi->ntfy;
>  	ret = ucsi_send_command(ucsi, command, NULL, 0);
>  	if (ret < 0) {
> +		if (++ucsi->resume_retries < 5) {
> +			queue_delayed_work(system_long_wq, &ucsi->resume_work,
> +					   msecs_to_jiffies(500));
> +			return;
> +		}
>  		dev_err(ucsi->dev, "failed to re-enable notifications (%d)\n", ret);
>  		return;
>  	}
> @@ -2187,6 +2192,7 @@ int ucsi_suspend(struct ucsi *ucsi)
>  	 * EC is stopped for suspend; state is re-read on resume.
>  	 */
>  	cancel_delayed_work_sync(&ucsi->work);
> +	cancel_delayed_work_sync(&ucsi->resume_work);
>  
>  	if (!ucsi->connector)
>  		return 0;
> @@ -2200,8 +2206,10 @@ EXPORT_SYMBOL_GPL(ucsi_suspend);
>  
>  int ucsi_resume(struct ucsi *ucsi)
>  {
> -	if (ucsi->connector)
> -		queue_work(system_long_wq, &ucsi->resume_work);
> +	if (ucsi->connector) {
> +		ucsi->resume_retries = 0;
> +		queue_delayed_work(system_long_wq, &ucsi->resume_work, 0);
> +	}
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(ucsi_resume);
> @@ -2299,7 +2307,7 @@ struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops)
>  	if (!ucsi)
>  		return ERR_PTR(-ENOMEM);
>  
> -	INIT_WORK(&ucsi->resume_work, ucsi_resume_work);
> +	INIT_DELAYED_WORK(&ucsi->resume_work, ucsi_resume_work);
>  	INIT_DELAYED_WORK(&ucsi->work, ucsi_init_work);
>  	mutex_init(&ucsi->ppm_lock);
>  	init_completion(&ucsi->complete);
> @@ -2365,7 +2373,7 @@ void ucsi_unregister(struct ucsi *ucsi)
>  
>  	/* Make sure that we are not in the middle of driver initialization */
>  	cancel_delayed_work_sync(&ucsi->work);
> -	cancel_work_sync(&ucsi->resume_work);
> +	cancel_delayed_work_sync(&ucsi->resume_work);
>  
>  	ucsi_debugfs_unregister(ucsi);
>  
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index dc594388dcd0..1996f04ed5e6 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -484,7 +484,8 @@ struct ucsi {
>  	struct ucsi_connector *connector;
>  	struct ucsi_debugfs_entry *debugfs;
>  
> -	struct work_struct resume_work;
> +	struct delayed_work resume_work;
> +	int resume_retries;
>  	struct delayed_work work;
>  	int work_count;
>  #define UCSI_ROLE_SWITCH_RETRY_PER_HZ	10
> 
> base-commit: bdab5605259ba5d6ff927c1a85cc83eb3ecfdacc
> -- 
> 2.55.0.737.g08866a6d13-goog

-- 
heikki

Re: [PATCH v1] usb: typec: ucsi: allow retries of ucsi_resume_work

Posted by Benson Leung 1 month, 1 week ago

On Tue, Aug 18, 2026 at 08:57:17PM +0000, Jameson Thies wrote:
> On resume, the UCSI driver will re-enable notifications by sending
> SET_NOTIFICATION_ENABLE. The LPM/PPM may be busy during system
> resume causing SET_NOTIFICATION_ENABLE to fail and preventing the UCSI
> driver from receiving connection status changes.
> 
> Change resume work to a delayed workqueue to allow retries on failed
> SET_NOTIFICATION_ENABLED commands. Additionally, cancel resume work
> on suspend to prevent pending resume commands from impacting suspend.
> 
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Benson Leung <bleung@chromium.org>


> ---
>  drivers/usb/typec/ucsi/ucsi.c | 18 +++++++++++++-----
>  drivers/usb/typec/ucsi/ucsi.h |  3 ++-
>  2 files changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index bef3f9b71d71..5c67f0990dd3 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -2158,7 +2158,7 @@ static int ucsi_init(struct ucsi *ucsi)
>  
>  static void ucsi_resume_work(struct work_struct *work)
>  {
> -	struct ucsi *ucsi = container_of(work, struct ucsi, resume_work);
> +	struct ucsi *ucsi = container_of(to_delayed_work(work), struct ucsi, resume_work);
>  	struct ucsi_connector *con;
>  	u64 command;
>  	int ret;
> @@ -2167,6 +2167,11 @@ static void ucsi_resume_work(struct work_struct *work)
>  	command = UCSI_SET_NOTIFICATION_ENABLE | ucsi->ntfy;
>  	ret = ucsi_send_command(ucsi, command, NULL, 0);
>  	if (ret < 0) {
> +		if (++ucsi->resume_retries < 5) {
> +			queue_delayed_work(system_long_wq, &ucsi->resume_work,
> +					   msecs_to_jiffies(500));
> +			return;
> +		}
>  		dev_err(ucsi->dev, "failed to re-enable notifications (%d)\n", ret);
>  		return;
>  	}
> @@ -2187,6 +2192,7 @@ int ucsi_suspend(struct ucsi *ucsi)
>  	 * EC is stopped for suspend; state is re-read on resume.
>  	 */
>  	cancel_delayed_work_sync(&ucsi->work);
> +	cancel_delayed_work_sync(&ucsi->resume_work);
>  
>  	if (!ucsi->connector)
>  		return 0;
> @@ -2200,8 +2206,10 @@ EXPORT_SYMBOL_GPL(ucsi_suspend);
>  
>  int ucsi_resume(struct ucsi *ucsi)
>  {
> -	if (ucsi->connector)
> -		queue_work(system_long_wq, &ucsi->resume_work);
> +	if (ucsi->connector) {
> +		ucsi->resume_retries = 0;
> +		queue_delayed_work(system_long_wq, &ucsi->resume_work, 0);
> +	}
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(ucsi_resume);
> @@ -2299,7 +2307,7 @@ struct ucsi *ucsi_create(struct device *dev, const struct ucsi_operations *ops)
>  	if (!ucsi)
>  		return ERR_PTR(-ENOMEM);
>  
> -	INIT_WORK(&ucsi->resume_work, ucsi_resume_work);
> +	INIT_DELAYED_WORK(&ucsi->resume_work, ucsi_resume_work);
>  	INIT_DELAYED_WORK(&ucsi->work, ucsi_init_work);
>  	mutex_init(&ucsi->ppm_lock);
>  	init_completion(&ucsi->complete);
> @@ -2365,7 +2373,7 @@ void ucsi_unregister(struct ucsi *ucsi)
>  
>  	/* Make sure that we are not in the middle of driver initialization */
>  	cancel_delayed_work_sync(&ucsi->work);
> -	cancel_work_sync(&ucsi->resume_work);
> +	cancel_delayed_work_sync(&ucsi->resume_work);
>  
>  	ucsi_debugfs_unregister(ucsi);
>  
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index dc594388dcd0..1996f04ed5e6 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -484,7 +484,8 @@ struct ucsi {
>  	struct ucsi_connector *connector;
>  	struct ucsi_debugfs_entry *debugfs;
>  
> -	struct work_struct resume_work;
> +	struct delayed_work resume_work;
> +	int resume_retries;
>  	struct delayed_work work;
>  	int work_count;
>  #define UCSI_ROLE_SWITCH_RETRY_PER_HZ	10
> 
> base-commit: bdab5605259ba5d6ff927c1a85cc83eb3ecfdacc
> -- 
> 2.55.0.737.g08866a6d13-goog
>