From patchwork Wed Jul 4 12:43:48 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: archit taneja X-Patchwork-Id: 1155891 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 00471DFF0F for ; Wed, 4 Jul 2012 12:45:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751396Ab2GDMpQ (ORCPT ); Wed, 4 Jul 2012 08:45:16 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:51718 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751153Ab2GDMpP (ORCPT ); Wed, 4 Jul 2012 08:45:15 -0400 Received: from dlelxv30.itg.ti.com ([172.17.2.17]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id q64Cj8GO020141; Wed, 4 Jul 2012 07:45:08 -0500 Received: from DLEE74.ent.ti.com (dlee74.ent.ti.com [157.170.170.8]) by dlelxv30.itg.ti.com (8.13.8/8.13.8) with ESMTP id q64Cj8Xd013694; Wed, 4 Jul 2012 07:45:08 -0500 Received: from dlelxv23.itg.ti.com (172.17.1.198) by DLEE74.ent.ti.com (157.170.170.8) with Microsoft SMTP Server id 14.1.323.3; Wed, 4 Jul 2012 07:45:08 -0500 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dlelxv23.itg.ti.com (8.13.8/8.13.8) with ESMTP id q64Cj8o6005750; Wed, 4 Jul 2012 07:45:08 -0500 Received: from localhost (a0393947pc.apr.dhcp.ti.com [172.24.137.248]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id q64Cj5W16642; Wed, 4 Jul 2012 07:45:06 -0500 (CDT) From: Archit Taneja To: CC: , , , , Subject: [PATCH 1/2] OMAPDSS: Use PM notifiers for system suspend Date: Wed, 4 Jul 2012 18:13:48 +0530 Message-ID: <1341405829-16964-2-git-send-email-archit@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1341405829-16964-1-git-send-email-archit@ti.com> References: <1341405829-16964-1-git-send-email-archit@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org From: Tomi Valkeinen The current way how omapdss handles system suspend and resume is that omapdss device (a platform device, which is not part of the device hierarchy of the DSS HW devices, like DISPC and DSI, or panels.) uses the suspend and resume callbacks from platform_driver to handle system suspend. It does this by disabling all enabled panels on suspend, and resuming the previously disabled panels on resume. This presents a few problems. One is that as omapdss device is not related to the panel devices or the DSS HW devices, there's no ordering in the suspend process. This means that suspend could be first ran for DSS HW devices and panels, and only then for omapdss device. Currently this is not a problem, as DSS HW devices and panels do not handle suspend. Another, more pressing problem, is that when suspending or resuming, the runtime PM functions return -EACCES as runtime PM is disabled during system suspend. This causes the driver to print warnings, and operations to fail as they think that they failed to bring up the HW. This patch changes the omapdss suspend handling to use PM notifiers, which are called before suspend and after resume. This way we have a normally functioning system when we are suspending and resuming the panels. This patch, I believe, creates a problem that somebody could enable or disable a panel between PM_SUSPEND_PREPARE and the system suspend, and similarly the other way around in resume. I choose to ignore the problem for now, as it sounds rather unlikely, and if it happens, it's not fatal. In the long run the system suspend handling of omapdss and panels should be thought out properly. The current approach feels rather hacky. Perhaps the panel drivers should handle system suspend, or the users of omapdss (omapfb, omapdrm) should handle system suspend. Note that after this patch we could probably revert 0eaf9f52e94f756147dbfe1faf1f77a02378dbf9 (OMAPDSS: use sync versions of pm_runtime_put). But as I said, this patch may be temporary, so let's leave the sync version still in place. Signed-off-by: Tomi Valkeinen Reported-by: Jassi Brar Tested-by: Jassi Brar Tested-by: Joe Woodward --- drivers/video/omap2/dss/core.c | 45 ++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 16 deletions(-) diff --git a/drivers/video/omap2/dss/core.c b/drivers/video/omap2/dss/core.c index 5066eee..c35a248 100644 --- a/drivers/video/omap2/dss/core.c +++ b/drivers/video/omap2/dss/core.c @@ -32,6 +32,7 @@ #include #include #include +#include #include