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, 1 insertions, 15 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 46a88ae9c46a..ab4ad18d6ef3 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -768,9 +768,6 @@ static const char *ftdi_chip_name[] = {
 };
 
 
-/* Constants for read urb and write urb */
-#define BUFSZ 512
-
 /* Used for TIOCMIWAIT */
 #define FTDI_STATUS_B0_MASK     (FTDI_RS0_CTS | FTDI_RS0_DSR | FTDI_RS0_RI | FTDI_RS0_RLSD)
 #define FTDI_STATUS_B1_MASK     (FTDI_RS_BI)
@@ -821,6 +818,7 @@ static struct usb_serial_driver ftdi_sio_device = {
         .usb_driver =           &ftdi_driver,
         .id_table =             id_table_combined,
         .num_ports =            1,
+        .bulk_in_size =         512,
         .probe =                ftdi_sio_probe,
         .port_probe =           ftdi_sio_port_probe,
         .port_remove =          ftdi_sio_port_remove,
@@ -1552,18 +1550,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
         if (quirk && quirk->port_probe)
                 quirk->port_probe(priv);
 
-        /* Increase the size of read buffers */
-        kfree(port->bulk_in_buffer);
-        port->bulk_in_buffer = kmalloc(BUFSZ, GFP_KERNEL);
-        if (!port->bulk_in_buffer) {
-                kfree(priv);
-                return -ENOMEM;
-        }
-        if (port->read_urb) {
-                port->read_urb->transfer_buffer = port->bulk_in_buffer;
-                port->read_urb->transfer_buffer_length = BUFSZ;
-        }
-
         priv->port = port;
 
         /* Free port's existing write urb and transfer buffer. */