firewire: cdev: amendment to "add ioctl to query maximum transmission speed"

The as yet unreleased FW_CDEV_IOC_GET_SPEED ioctl puts only a single
integer into the parameter buffer.  We can use ioctl()'s return value
instead.

(Also: Some whitespace change in firewire-cdev.h.)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-cdev.c

@@ -1214,13 +1214,14 @@ static int ioctl_deallocate_iso_resource_once(struct client *client, void *buffe
 	return init_iso_resource(client, request, ISO_RES_DEALLOC_ONCE);
 }
 
+/*
+ * Returns a speed code:  Maximum speed to or from this device,
+ * limited by the device's link speed, the local node's link speed,
+ * and all PHY port speeds between the two links.
+ */
 static int ioctl_get_speed(struct client *client, void *buffer)
 {
-	struct fw_cdev_get_speed *request = buffer;
-
-	request->max_speed = client->device->max_speed;
-
-	return 0;
+	return client->device->max_speed;
 }
 
 static int ioctl_send_broadcast_request(struct client *client, void *buffer)

include/linux/firewire-cdev.h

@@ -244,7 +244,7 @@ union fw_cdev_event {
 #define FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE      _IOW('#', 0x0e, struct fw_cdev_deallocate)
 #define FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE   _IOW('#', 0x0f, struct fw_cdev_allocate_iso_resource)
 #define FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE_ONCE _IOW('#', 0x10, struct fw_cdev_allocate_iso_resource)
-#define FW_CDEV_IOC_GET_SPEED                    _IOR('#', 0x11, struct fw_cdev_get_speed)
+#define FW_CDEV_IOC_GET_SPEED                     _IO('#', 0x11) /* returns speed code */
 #define FW_CDEV_IOC_SEND_BROADCAST_REQUEST       _IOW('#', 0x12, struct fw_cdev_send_request)
 #define FW_CDEV_IOC_SEND_STREAM_PACKET           _IOW('#', 0x13, struct fw_cdev_send_stream_packet)
 
@@ -601,15 +601,6 @@ struct fw_cdev_allocate_iso_resource {
 	__u32 handle;
 };
 
-/**
- * struct fw_cdev_get_speed - Query maximum speed to or from this device
- * @max_speed:	Speed code; minimum of the device's link speed, the local node's
- *		link speed, and all PHY port speeds between the two links
- */
-struct fw_cdev_get_speed {
-	__u32 max_speed;
-};
-
 /**
  * struct fw_cdev_send_stream_packet - send an asynchronous stream packet
  * @generation:   Bus generation where the packet is valid