From 25d514ca227e1ac81d0906a4ccf2aa171f50a600 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 17 Mar 2010 23:06:07 +0100 Subject: USB: serial: re-implement multi-urb writes in generic driver Use dynamic transfer buffer sizes since it is more efficient to let the host controller do the partitioning to fit endpoint size. This way we also do not use more than one urb per write request. Replace max_in_flight_urbs with multi_urb_write flag in struct usb_serial_driver to enable multi-urb writes. Use MAX_TX_URBS=40 and a max buffer size of PAGE_SIZE to prevent DoS attacks. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/serial.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/linux/usb') diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index ff8872eba3ac..2a3283761600 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -60,6 +60,8 @@ enum port_dev_state { * @write_urb: pointer to the bulk out struct urb for this port. * @write_fifo: kfifo used to buffer outgoing data * @write_urb_busy: port`s writing status + * @tx_bytes: number of bytes currently in host stack queues + * @tx_urbs: number of urbs currently in host stack queues * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this * port. * @write_wait: a wait_queue_head_t used by the port. @@ -98,8 +100,8 @@ struct usb_serial_port { int write_urb_busy; __u8 bulk_out_endpointAddress; - int tx_bytes_flight; - int urbs_in_flight; + int tx_bytes; + int tx_urbs; wait_queue_head_t write_wait; struct work_struct work; @@ -223,7 +225,8 @@ struct usb_serial_driver { struct device_driver driver; struct usb_driver *usb_driver; struct usb_dynids dynids; - int max_in_flight_urbs; + + unsigned char multi_urb_write:1; size_t bulk_in_size; size_t bulk_out_size; -- cgit v1.2.1