[PATCH 1/1] staging: nvec: fix power-off path to not depend on workqueue

[PATCH 1/1] staging: nvec: fix power-off path to not depend on workqueue

[Aayush7352]

nvec_power_off() uses nvec_write_async() which queues work via schedule_work().
During system shutdown or reboot, workqueues may be frozen, so the
AP_PWR_DOWN message never reaches the embedded controller and the
system hangs instead of powering off.

Fix by calling nvec_request_master() directly after queuing the power-off
messages, processing the TX queue synchronously in the power-off context.
Also add a NULL guard for nvec_power_handle.

This addresses the TODO item "add atomic ops in order to fix shutoff/reboot
problems" in drivers/staging/nvec/TODO.
---
 drivers/staging/nvec/nvec.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
index 88c416ee0..938ea8f34 100644
--- a/drivers/staging/nvec/nvec.c
+++ b/drivers/staging/nvec/nvec.c
@@ -774,10 +774,23 @@ static void nvec_disable_i2c_slave(struct nvec_chip *nvec)
 
 static void nvec_power_off(void)
 {
+	struct nvec_chip *nvec = nvec_power_handle;
 	char ap_pwr_down[] = { NVEC_SLEEP, AP_PWR_DOWN };
 
-	nvec_toggle_global_events(nvec_power_handle, false);
-	nvec_write_async(nvec_power_handle, ap_pwr_down, 2);
+	if (!nvec)
+		return;
+
+	nvec_toggle_global_events(nvec, false);
+	nvec_write_async(nvec, ap_pwr_down, 2);
+
+	/*
+	 * Process the TX queue directly instead of relying on the
+	 * workqueue.  Workqueues may be frozen during the power-off
+	 * sequence, so schedule_work() from nvec_write_async() may
+	 * not execute, leaving the AP_PWR_DOWN message unsent and
+	 * the system unable to power off.
+	 */
+	nvec_request_master(&nvec->tx_work);
 }
 
 static int tegra_nvec_probe(struct platform_device *pdev)
-- 
2.55.0

Re: [PATCH 1/1] staging: nvec: fix power-off path to not depend on workqueue

[Dan Carpenter]

On Tue, Jul 21, 2026 at 02:17:27PM +0530, Aayush7352 wrote:

You need to use your real name.

> nvec_power_off() uses nvec_write_async() which queues work via schedule_work().
> During system shutdown or reboot, workqueues may be frozen, so the
> AP_PWR_DOWN message never reaches the embedded controller and the
> system hangs instead of powering off.
> 
> Fix by calling nvec_request_master() directly after queuing the power-off
> messages, processing the TX queue synchronously in the power-off context.
> Also add a NULL guard for nvec_power_handle.
> 
> This addresses the TODO item "add atomic ops in order to fix shutoff/reboot
> problems" in drivers/staging/nvec/TODO.

Missing signed off by line.

> ---
  ^^^

This is a common thing where people ask the AI to fix the todo...  You
need to say under the --- cut off line that the patch has not been
tested.

The TODO is kind of vague.  "add atomic ops in order to fix
shutoff/reboot"...  I suppose this could be the fix for it??  Anyway,
Marc wrote that todo so we'll see if that's what he meant.

regards,
dan carpenter