USB: serial: report unsupported break signalling

jhovold · jhovold · commit c9d934053d9e · 2023-06-07T17:00:24.000+02:00
Instead of returning success when a driver does not support break
signalling, return an error to let user space know and to avoid waiting
when break is not supported.

Tested-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
@@ -541,7 +541,7 @@ static int serial_break(struct tty_struct *tty, int break_state)
 	if (port->serial->type->break_ctl)
 		return port->serial->type->break_ctl(tty, break_state);
 
-	return 0;
+	return -ENOTTY;
 }
 
 static int serial_proc_show(struct seq_file *m, void *v)

Original file line number	Diff line number	Diff line change
`@@ -541,7 +541,7 @@ static int serial_break(struct tty_struct *tty, int break_state)`
`541`	`541`	`if (port->serial->type->break_ctl)`
`542`	`542`	`return port->serial->type->break_ctl(tty, break_state);`
`543`	`543`
`544`		`- return 0;`
	`544`	`+ return -ENOTTY;`
`545`	`545`	`}`
`546`	`546`
`547`	`547`	`static int serial_proc_show(struct seq_file m, void v)`