[PATCH v2] serial: 8250_omap: fix wake irq cleared during suspend

[PATCH v2] serial: 8250_omap: fix wake irq cleared during suspend

[Kendall Willis]

The wake irq was cleared in shutdown(), which runs during the suspend
sequence, making it impossible to wake the system via UART.
Move wake irq setup to probe() and teardown to remove() so the irq
remains armed during suspend when the UART is a wakeup source.

Cc: stable@vger.kernel.org
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Kendall Willis <k-willis@ti.com>
---
Changes in v2:
- Move dev_pm_clear_wake_irq() before pm_runtime_put_sync() to avoid
  potential race condition.
- Link to v1: https://lore.kernel.org/r/20260824-uart-wakeirq-fix-v1-1-6d81a230a1c4@ti.com
---
 drivers/tty/serial/8250/8250_omap.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 3c7775df27effd309419b413c791b46688d4aacd..ceecb39fb82da255377931dbb5cf83fd57eaf164 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -711,12 +711,6 @@ static int omap_8250_startup(struct uart_port *port)
 	struct uart_8250_dma *dma = &priv->omap8250_dma;
 	int ret;
 
-	if (priv->wakeirq) {
-		ret = dev_pm_set_dedicated_wake_irq(port->dev, priv->wakeirq);
-		if (ret)
-			return ret;
-	}
-
 #ifdef CONFIG_PM
 	up->capabilities |= UART_CAP_RPM;
 #endif
@@ -787,7 +781,6 @@ static void omap_8250_shutdown(struct uart_port *port)
 	}
 
 	disable_irq_nosync(port->irq);
-	dev_pm_clear_wake_irq(port->dev);
 
 	serial8250_release_dma(up);
 	up->dma = NULL;
@@ -1588,6 +1581,12 @@ static int omap8250_probe(struct platform_device *pdev)
 
 	priv->wakeirq = irq_of_parse_and_map(np, 1);
 
+	if (priv->wakeirq) {
+		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev, priv->wakeirq);
+		if (ret)
+			goto err;
+	}
+
 	ret = serial8250_register_8250_port(&up);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "unable to register 8250 port\n");
@@ -1603,6 +1602,7 @@ static int omap8250_probe(struct platform_device *pdev)
 
 	return 0;
 err:
+	dev_pm_clear_wake_irq(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	flush_work(&priv->qos_work);
@@ -1625,6 +1625,7 @@ static void omap8250_remove(struct platform_device *pdev)
 	omap_8250_shutdown(&up->port);
 	serial8250_unregister_port(priv->line);
 	priv->line = -ENODEV;
+	dev_pm_clear_wake_irq(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	flush_work(&priv->qos_work);

---
base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f
change-id: 20260824-uart-wakeirq-fix-33f470ac7245

Best regards,
-- 
Kendall Willis <k-willis@ti.com>

Re: [PATCH v2] serial: 8250_omap: fix wake irq cleared during suspend

[Sebastian Andrzej Siewior]

On 2026-08-25 17:06:07 [-0500], Kendall Willis wrote:
> The wake irq was cleared in shutdown(), which runs during the suspend
> sequence, making it impossible to wake the system via UART.
> Move wake irq setup to probe() and teardown to remove() so the irq
> remains armed during suspend when the UART is a wakeup source.

The omap-serial has the same problem, doesn't it?
I would still like to see an ACK from Tony here.

> Cc: stable@vger.kernel.org
> Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
> Signed-off-by: Kendall Willis <k-willis@ti.com>

Sebastian

Re: [PATCH v2] serial: 8250_omap: fix wake irq cleared during suspend

[Tony Lindgren]

On Wed, Aug 26, 2026 at 04:53:07PM +0200, Sebastian Andrzej Siewior wrote:
> On 2026-08-25 17:06:07 [-0500], Kendall Willis wrote:
> > The wake irq was cleared in shutdown(), which runs during the suspend
> > sequence, making it impossible to wake the system via UART.
> > Move wake irq setup to probe() and teardown to remove() so the irq
> > remains armed during suspend when the UART is a wakeup source.
> 
> The omap-serial has the same problem, doesn't it?

Yes likely.

> I would still like to see an ACK from Tony here.

Maybe there was some deferred probe type issue with getting the wakeirq
earlier.

In any case if there was an issue getting the wakeirq it should be handled
nowadays with -EPROBE_DEFER.

Reviewed-by: Tony Lindgren <tony.lindgren@linux.intel.com>