patch "USB: serial: suppress driver bind attributes" added to usb-linus

This is a note to let you know that I've just added the patch titled

USB: serial: suppress driver bind attributes

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From fdb838efa31e1ed9a13ae6ad0b64e30fdbd00570 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Thu, 16 Jan 2020 17:07:05 +0100
Subject: USB: serial: suppress driver bind attributes

USB-serial drivers must not be unbound from their ports before the corresponding USB driver is unbound from the parent interface so suppress the bind and unbind attributes.

Unbinding a serial driver while it's port is open is a sure way to trigger a crash as any driver state is released on unbind while port hangup is handled on the parent USB interface level. Drivers for multiport devices where ports share a resource such as an interrupt endpoint also generally cannot handle individual ports going away.

---
 drivers/usb/serial/usb-serial.c | 3 +++
 1 file changed, 3 insertions(+)

index 8f066bb55d7d..dc7a65b9ec98 100644
@@ -1317,6 +1317,9 @@ static int usb_serial_register(struct usb_serial_driver *driver)
 		return -EINVAL;
 	}
 
+	/* Prevent individual ports from being unbound. */
+	driver->driver.suppress_bind_attrs = true;
+
 	usb_serial_operations_init(driver);
 
 	/* Add this device to our list of devices */

2.25.0