From be585c07dd577faac26014db4246e6d7c7a131e7 Mon Sep 17 00:00:00 2001 From: Jay Fenlason Date: Wed, 1 Oct 2008 18:13:20 -0400 Subject: [PATCH] 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(-) diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index 0f0e271f97fa..4d078e99c017 100644 --- a/include/linux/firewire-cdev.h +++ b/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;