From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932456AbcFIPHw (ORCPT ); Thu, 9 Jun 2016 11:07:52 -0400 Received: from mail-yw0-f195.google.com ([209.85.161.195]:34868 "EHLO mail-yw0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932382AbcFIPHu (ORCPT ); Thu, 9 Jun 2016 11:07:50 -0400 From: Gustavo Padovan To: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, Daniel Stone , Daniel Vetter , Rob Clark , Greg Hackmann , John Harrison , laurent.pinchart@ideasonboard.com, seanpaul@google.com, marcheu@google.com, m.chehab@samsung.com, Sumit Semwal , Maarten Lankhorst , Gustavo Padovan Subject: [PATCH 3/3] Documentation: add doc for sync_file_get_fence() Date: Thu, 9 Jun 2016 12:05:30 -0300 Message-Id: <1465484730-8128-3-git-send-email-gustavo@padovan.org> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1465484730-8128-1-git-send-email-gustavo@padovan.org> References: <1465484730-8128-1-git-send-email-gustavo@padovan.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Gustavo Padovan Document the new function added to sync_file.c v2: Adapt to fence_array Signed-off-by: Gustavo Padovan --- Documentation/sync_file.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/Documentation/sync_file.txt b/Documentation/sync_file.txt index eaf8297..46f5769 100644 --- a/Documentation/sync_file.txt +++ b/Documentation/sync_file.txt @@ -64,6 +64,25 @@ The sync_file fd now can be sent to userspace. If the creation process fail, or the sync_file needs to be released by any other reason fput(sync_file->file) should be used. +Receiving Sync Files from Userspace +----------------------------------- + +When userspace needs to send an in-fence to the driver it pass file descriptor +of the Sync File to the kernel. The kernel then can retrieve the sync_file +from it. + +Interface: + struct fence *sync_file_get_fence(int fd); + + +The function return a struct fence pointer referencing the fence(s) in the Sync +File. If the Sync File contains only one fence, this fence is returned. But if +has more than one fence a fence_array[3] is returned. However the callers only +see the arrays' base class which is struct fence. In both cases a reference to +the returned fence is held. + + References: [1] struct sync_file in include/linux/sync_file.h [2] All interfaces mentioned above defined in include/linux/sync_file.h +[1] struct fence_array in include/linux/fence-array.h -- 2.5.5