USB: cypress_m8: Feature buffer fixes

cypress_m8: Feature buffer fixes

From: Mike Isely <isely@pobox.com>

Don't hardcode the feature buffer size; use sizeof() instead.  That
way we can easily specify the size in a single spot.  Speaking of the
feature buffer size, the Cypress app note (and further testing with a
DeLorme Earthmate) suggests that this size should be 5 not 8 bytes.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 22 insertions, 14 deletions

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 779d07851a4..155b82a25d1 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -290,7 +290,7 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
 {
         int new_baudrate = 0, retval = 0, tries = 0;
         struct cypress_private *priv;
-        __u8 feature_buffer[8];
+        __u8 feature_buffer[5];
         unsigned long flags;
 
         dbg("%s", __FUNCTION__);
@@ -353,7 +353,7 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
                         }
                         dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
                         
-                        memset(feature_buffer, 0, 8);
+                        memset(feature_buffer, 0, sizeof(feature_buffer));
                         /* fill the feature_buffer with new configuration */
                         *((u_int32_t *)feature_buffer) = new_baudrate;
 
@@ -370,16 +370,20 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
                             feature_buffer[2], feature_buffer[3], feature_buffer[4]);
                         
                         do {
-                        retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
-                                                  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
-                                                          0x0300, 0, feature_buffer, 8, 500);
+                                retval = usb_control_msg(port->serial->dev,
+                                                usb_sndctrlpipe(port->serial->dev, 0),
+                                                HID_REQ_SET_REPORT,
+                                                USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+                                                0x0300, 0, feature_buffer,
+                                                sizeof(feature_buffer), 500);
 
                                 if (tries++ >= 3)
                                         break;
 
-                        } while (retval != 8 && retval != -ENODEV);
+                        } while (retval != sizeof(feature_buffer) &&
+                                 retval != -ENODEV);
 
-                        if (retval != 8) {
+                        if (retval != sizeof(feature_buffer)) {
                                 err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
                                 cypress_set_dead(port);
                         } else {
@@ -393,19 +397,23 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
                 case CYPRESS_GET_CONFIG:
                         dbg("%s - retreiving serial line settings", __FUNCTION__);
                         /* set initial values in feature buffer */
-                        memset(feature_buffer, 0, 8);
+                        memset(feature_buffer, 0, sizeof(feature_buffer));
 
                         do {
-                        retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
-                                                  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
-                                                          0x0300, 0, feature_buffer, 8, 500);
-                                
+                                retval = usb_control_msg(port->serial->dev,
+                                                usb_rcvctrlpipe(port->serial->dev, 0),
+                                                HID_REQ_GET_REPORT,
+                                                USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
+                                                0x0300, 0, feature_buffer,
+                                                sizeof(feature_buffer), 500);
+
                                 if (tries++ >= 3)
                                         break;
 
-                        } while (retval != 5 && retval != -ENODEV);
+                        } while (retval != sizeof(feature_buffer) &&
+                                 retval != -ENODEV);
 
-                        if (retval != 5) {
+                        if (retval != sizeof(feature_buffer)) {
                                 err("%s - failed to retrieve serial line settings - %d", __FUNCTION__, retval);
                                 cypress_set_dead(port);
                                 return retval;