Date: Wed, 1 Oct 2008 18:13:20 -0400 From: Jay Fenlason Subject: firewire: Add more documentation to firewire-cdev.h Signed-off-by: Jay Fenlason Signed-off-by: Stefan Richter --- include/linux/firewire-cdev.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) Index: linux/include/linux/firewire-cdev.h =================================================================== --- linux.orig/include/linux/firewire-cdev.h +++ linux/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;