USB: serial: allow drivers to define bulk buffer sizes

Allow drivers to define custom bulk in/out buffer sizes in struct
usb_serial_driver. If not set, fall back to the default buffer size
which matches the endpoint size.

Three drivers are currently freeing the pre-allocated buffers and
allocating larger ones to achieve this at port probe (ftdi_sio) or even
at port open (ipaq and iuu_phoenix), which needless to say is suboptimal.

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

1 files changed, 2 insertions, 26 deletions

diff --git a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
index 3fea9298eb15..87b11461bf11 100644
--- a/drivers/usb/serial/ipaq.c
+++ b/drivers/usb/serial/ipaq.c
@@ -571,6 +571,8 @@ static struct usb_serial_driver ipaq_device = {
         .description =          "PocketPC PDA",
         .usb_driver =           &ipaq_driver,
         .id_table =             ipaq_id_table,
+        .bulk_in_size =         URBDATA_SIZE,
+        .bulk_out_size =        URBDATA_SIZE,
         .open =                 ipaq_open,
         .close =                ipaq_close,
         .attach =               ipaq_startup,
@@ -628,32 +630,6 @@ static int ipaq_open(struct tty_struct *tty,
                 priv->free_len += PACKET_SIZE;
         }
 
-        /*
-         * Lose the small buffers usbserial provides. Make larger ones.
-         */
-
-        kfree(port->bulk_in_buffer);
-        kfree(port->bulk_out_buffer);
-        /* make sure the generic serial code knows */
-        port->bulk_out_buffer = NULL;
-
-        port->bulk_in_buffer = kmalloc(URBDATA_SIZE, GFP_KERNEL);
-        if (port->bulk_in_buffer == NULL)
-                goto enomem;
-
-        port->bulk_out_buffer = kmalloc(URBDATA_SIZE, GFP_KERNEL);
-        if (port->bulk_out_buffer == NULL) {
-                /* the buffer is useless, free it */
-                kfree(port->bulk_in_buffer);
-                port->bulk_in_buffer = NULL;
-                goto enomem;
-        }
-        port->read_urb->transfer_buffer = port->bulk_in_buffer;
-        port->write_urb->transfer_buffer = port->bulk_out_buffer;
-        port->read_urb->transfer_buffer_length = URBDATA_SIZE;
-        port->bulk_out_size = port->write_urb->transfer_buffer_length
-                                                        = URBDATA_SIZE;
-
         msleep(1000*initial_wait);
 
         /*