USB: serial: generalise generic read implementation

Add process_read_urb to usb_serial_driver so that a driver can rely on
the generic read (and throttle) mechanism but still do device specific
processing of incoming data (such as adding tty_flags before pushing to
line discipline).

The default generic implementation handles sysrq for consoles but
otherwise simply pushes to tty.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 4 insertions, 2 deletions

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index e16c0b234cc9..176f1257b664 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -408,7 +408,7 @@ int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
 }
 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
 
-static void usb_serial_generic_process_read_urb(struct urb *urb)
+void usb_serial_generic_process_read_urb(struct urb *urb)
 {
         struct usb_serial_port *port = urb->context;
         struct tty_struct *tty;
@@ -433,6 +433,7 @@ static void usb_serial_generic_process_read_urb(struct urb *urb)
         tty_flip_buffer_push(tty);
         tty_kref_put(tty);
 }
+EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
 
 void usb_serial_generic_read_bulk_callback(struct urb *urb)
 {
@@ -451,7 +452,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
 
         usb_serial_debug_data(debug, &port->dev, __func__,
                                                 urb->actual_length, data);
-        usb_serial_generic_process_read_urb(urb);
+        port->serial->type->process_read_urb(urb);
 
         /* Throttle the device if requested by tty */
         spin_lock_irqsave(&port->lock, flags);
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 538924627eba..1b924425089f 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1298,6 +1298,7 @@ static void fixup_generic(struct usb_serial_driver *device)
         set_to_generic_if_null(device, write_bulk_callback);
         set_to_generic_if_null(device, disconnect);
         set_to_generic_if_null(device, release);
+        set_to_generic_if_null(device, process_read_urb);
 }
 
 int usb_serial_register(struct usb_serial_driver *driver)