From patchwork Thu Feb 26 13:20:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 5897201 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 153BC9F269 for ; Fri, 27 Feb 2015 01:14:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 477C02020F for ; Fri, 27 Feb 2015 01:14:24 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 12D3A2021A for ; Fri, 27 Feb 2015 01:14:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C90F86E861; Thu, 26 Feb 2015 17:13:48 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by gabe.freedesktop.org (Postfix) with ESMTP id 6C4696E7C1 for ; Thu, 26 Feb 2015 05:21:18 -0800 (PST) Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id t1QDLGrj011724; Thu, 26 Feb 2015 07:21:16 -0600 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t1QDLF6P007354; Thu, 26 Feb 2015 07:21:15 -0600 Received: from dlep33.itg.ti.com (157.170.170.75) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.224.2; Thu, 26 Feb 2015 07:21:14 -0600 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t1QDKqkq005764; Thu, 26 Feb 2015 07:21:13 -0600 From: Tomi Valkeinen To: Laurent Pinchart , Subject: [PATCH 12/21] drm/omap: tiler: fix race condition with engine->async Date: Thu, 26 Feb 2015 15:20:20 +0200 Message-ID: <1424956829-22892-13-git-send-email-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.3.0 In-Reply-To: <1424956829-22892-1-git-send-email-tomi.valkeinen@ti.com> References: <1424956829-22892-1-git-send-email-tomi.valkeinen@ti.com> MIME-Version: 1.0 X-Mailman-Approved-At: Thu, 26 Feb 2015 17:13:46 -0800 Cc: Tomi Valkeinen , linux-omap@vger.kernel.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The tiler irq handler uses engine->async value, but the code that sets engine->async and enables the interrupt does not have a barrier. This may cause the irq handler to see the old value of engine->async, causing memory corruption. Reported-by: Harinarayan Bhatta Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/omapdrm/omap_dmm_tiler.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c index ef3d14d9cfa1..c4563af55a82 100644 --- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c +++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c @@ -273,6 +273,8 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait) /* mark whether it is async to denote list management in IRQ handler */ engine->async = wait ? false : true; + /* verify that the irq handler sees the 'async' value */ + smp_mb(); /* kick reload */ writel(engine->refill_pa,