Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: Add more documentation to firewire-cdev.h
  firewire: fix ioctl() return code
  firewire: fix setting tag and sy in iso transmission
  firewire: fw-sbp2: fix another small generation access bug
  firewire: fw-sbp2: enforce s/g segment size limit
  firewire: fw_send_request_sync()
  ieee1394: survive a few seconds connection loss
  ieee1394: nodemgr clean up class iterators
  ieee1394: dv1394, video1394: remove unnecessary expressions
  ieee1394: raw1394: make write() thread-safe
  ieee1394: raw1394: narrow down the state_mutex protected region
  ieee1394: raw1394: replace BKL by local mutex, make ioctl() and mmap() thread-safe
  ieee1394: sbp2: enforce s/g segment size limit
  ieee1394: sbp2: check for DMA mapping failures
  ieee1394: sbp2: stricter dma_sync
  ieee1394: Use DIV_ROUND_UP

include/linux/firewire-cdev.h

@@ -154,8 +154,13 @@ struct fw_cdev_event_iso_interrupt {
  * @request:       Valid if @common.type == %FW_CDEV_EVENT_REQUEST
  * @iso_interrupt: Valid if @common.type == %FW_CDEV_EVENT_ISO_INTERRUPT
  *
- * Convenience union for userspace use.  Events could be read(2) into a char
- * buffer and then cast to this union for further processing.
+ * Convenience union for userspace use.  Events could be read(2) into an
+ * appropriately aligned char buffer and then cast to this union for further
+ * processing.  Note that for a request, response or iso_interrupt event,
+ * the data[] or header[] may make the size of the full event larger than
+ * sizeof(union fw_cdev_event).  Also note that if you attempt to read(2)
+ * an event into a buffer that is not large enough for it, the data that does
+ * not fit will be discarded so that the next read(2) will return a new event.
  */
 union fw_cdev_event {
 	struct fw_cdev_event_common common;