[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.
This removes a lot of racy and buggy code by trying to check the status of the urb.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/usb-serial.h b/drivers/usb/serial/usb-serial.h
index d1f0c40..57f92f0 100644
--- a/drivers/usb/serial/usb-serial.h
+++ b/drivers/usb/serial/usb-serial.h
@@ -69,6 +69,7 @@
* usb_serial_port: structure for the specific ports of a device.
* @serial: pointer back to the struct usb_serial owner of this port.
* @tty: pointer to the corresponding tty for this port.
+ * @lock: spinlock to grab when updating portions of this structure.
* @number: the number of the port (the minor number).
* @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
* @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
@@ -98,6 +99,7 @@
struct usb_serial_port {
struct usb_serial * serial;
struct tty_struct * tty;
+ spinlock_t lock;
unsigned char number;
unsigned char * interrupt_in_buffer;
@@ -117,6 +119,7 @@
unsigned char * bulk_out_buffer;
int bulk_out_size;
struct urb * write_urb;
+ int write_urb_busy;
__u8 bulk_out_endpointAddress;
wait_queue_head_t write_wait;