From: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

If an external connector like M.2 is connected to the serdev controller
in DT, then the serdev devices may be created dynamically by the connector
driver. So do not return -ENODEV from of_serdev_register_devices() if the
static nodes are not found and the graph node is used.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/tty/serdev/core.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 25382c2d63e6..f8093b606dda 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/of_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
@@ -548,7 +549,13 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
 		} else
 			found = true;
 	}
-	if (!found)
+
+	/*
+	 * When the serdev controller is connected to an external connector like
+	 * M.2 in DT, then the serdev devices may be created dynamically by the
+	 * connector driver.
+	 */
+	if (!found && !of_graph_is_present(ctrl->dev.of_node))
 		return -ENODEV;
 
 	return 0;

-- 
2.48.1

On Mon, Jan 12, 2026 at 09:56:02PM +0530, Manivannan Sadhasivam via B4 Relay wrote:

> If an external connector like M.2 is connected to the serdev controller
> in DT, then the serdev devices may be created dynamically by the connector
> driver. So do not return -ENODEV from of_serdev_register_devices() if the
> static nodes are not found and the graph node is used.

...

> +	if (!found && !of_graph_is_present(ctrl->dev.of_node))

dev_of_node()

>  		return -ENODEV;

-- 
With Best Regards,
Andy Shevchenko

On Mon, Jan 12, 2026 at 09:23:58PM +0200, Andy Shevchenko wrote:
> On Mon, Jan 12, 2026 at 09:56:02PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> 
> > If an external connector like M.2 is connected to the serdev controller
> > in DT, then the serdev devices may be created dynamically by the connector
> > driver. So do not return -ENODEV from of_serdev_register_devices() if the
> > static nodes are not found and the graph node is used.
> 
> ...
> 
> > +	if (!found && !of_graph_is_present(ctrl->dev.of_node))
> 
> dev_of_node()
> 

Ack.

- Mani

-- 
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