diff mbox series

[V4] usb: serial: Fix mos7840 hangup on resume

Message ID 20240614224556.23215-1-d.smirnov@inbox.lv
State New
Headers show
Series [V4] usb: serial: Fix mos7840 hangup on resume | expand

Commit Message

Dmitry Smirnov June 14, 2024, 10:45 p.m. UTC
This patch addresses a kernel hang issue with the mos7840 driver when
PC resuming from a suspend with a device connected to the serial port.

This patch introduces two new functions: mos7840_suspend() and mos7840_resume().

Tested with Delock 87414 USB 2.0 to 4x serial adapter.

Signed-off-by: Dmitry Smirnov <d.smirnov@inbox.lv>
---
V4: Removed debug prints
V3: Code cleanup
V2: Reworked mos7840_suspend() based on comments from reviewer
V1: Initial version

 drivers/usb/serial/mos7840.c | 48 ++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)


base-commit: c3f38fa61af77b49866b006939479069cd451173
diff mbox series

Patch

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 8b0308d84270..2f4b2c8f4a48 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1737,6 +1737,52 @@  static void mos7840_port_remove(struct usb_serial_port *port)
 	kfree(mos7840_port);
 }
 
+static int mos7840_suspend(struct usb_serial *serial, pm_message_t message)
+{
+	struct moschip_port *mos7840_port;
+	struct usb_serial_port *port;
+	int i;
+
+	for (i = 0; i < serial->num_ports; ++i) {
+		port = serial->port[i];
+		if (!tty_port_initialized(&port->port))
+			continue;
+
+		mos7840_port = usb_get_serial_port_data(port);
+
+		usb_kill_urb(mos7840_port->read_urb);
+		mos7840_port->read_urb_busy = false;
+	}
+
+	return 0;
+}
+
+static int mos7840_resume(struct usb_serial *serial)
+{
+	struct moschip_port *mos7840_port;
+	struct usb_serial_port *port;
+	int res;
+	int i;
+
+	for (i = 0; i < serial->num_ports; ++i) {
+		port = serial->port[i];
+		if (!tty_port_initialized(&port->port))
+			continue;
+
+		mos7840_port = usb_get_serial_port_data(port);
+
+		if (port->bulk_in_size) {
+			res = usb_submit_urb(mos7840_port->read_urb, GFP_NOIO);
+			if (res) {
+				usb_kill_urb(mos7840_port->read_urb);
+				mos7840_port->read_urb_busy = false;
+			}
+		}
+	}
+
+	return 0;
+}
+
 static struct usb_serial_driver moschip7840_4port_device = {
 	.driver = {
 		   .owner = THIS_MODULE,
@@ -1764,6 +1810,8 @@  static struct usb_serial_driver moschip7840_4port_device = {
 	.port_probe = mos7840_port_probe,
 	.port_remove = mos7840_port_remove,
 	.read_bulk_callback = mos7840_bulk_in_callback,
+	.suspend = mos7840_suspend,
+	.resume = mos7840_resume,
 };
 
 static struct usb_serial_driver * const serial_drivers[] = {