From patchwork Fri Jul 13 20:10:31 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Hunter, Jon" X-Patchwork-Id: 1196801 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 2CAC2DFFFD for ; Fri, 13 Jul 2012 20:15:16 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SpmCg-0006Im-QH; Fri, 13 Jul 2012 20:11:06 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SpmCT-0006HA-1U for linux-arm-kernel@lists.infradead.org; Fri, 13 Jul 2012 20:10:54 +0000 Received: from dlelxv30.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id q6DKAcLI026288 for ; Fri, 13 Jul 2012 15:10:38 -0500 Received: from DFLE70.ent.ti.com (dfle70.ent.ti.com [128.247.5.40]) by dlelxv30.itg.ti.com (8.13.8/8.13.8) with ESMTP id q6DKAc2M008660 for ; Fri, 13 Jul 2012 15:10:38 -0500 Received: from dlelxv23.itg.ti.com (172.17.1.198) by dfle70.ent.ti.com (128.247.5.40) with Microsoft SMTP Server id 14.1.323.3; Fri, 13 Jul 2012 15:10:38 -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 q6DKAbLw016800; Fri, 13 Jul 2012 15:10:37 -0500 Received: from localhost (h0-101.vpn.ti.com [172.24.0.101]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id q6DKAbW19340; Fri, 13 Jul 2012 15:10:37 -0500 (CDT) From: Jon Hunter To: Tarun Kanti DebBarma Subject: [PATCH] ARM: OMAP2+: Fix dmtimer set source clock failure Date: Fri, 13 Jul 2012 15:10:31 -0500 Message-ID: <1342210231-2070-1-git-send-email-jon-hunter@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -6.9 (------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-6.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [192.94.94.40 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Jon Hunter , linux-arm X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Calling the dmtimer function omap_dm_timer_set_source() fails if following a call to pm_runtime_put() to disable the timer. For example the following sequence would fail to set the parent clock ... omap_dm_timer_stop(gptimer); omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ); The following error message would be seen ... omap_dm_timer_set_source: failed to set timer_32k_ck as parent The problem is that, by design, pm_runtime_put() simply decrements the usage count and returns before the timer has actually been disabled. Therefore, setting the parent clock failed because the timer was still active when the trying to set the parent clock. Setting a parent clock will fail if the clock you are setting the parent of has a non-zero usage count. To ensure that this does not fail use pm_runtime_put_sync() when disabling the timer. Note that this will not be seen on OMAP1 devices, because these devices do not use the clock framework for dmtimers. Signed-off-by: Jon Hunter --- arch/arm/plat-omap/dmtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c index 626ad8c..7b6689a 100644 --- a/arch/arm/plat-omap/dmtimer.c +++ b/arch/arm/plat-omap/dmtimer.c @@ -258,7 +258,7 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_enable); void omap_dm_timer_disable(struct omap_dm_timer *timer) { - pm_runtime_put(&timer->pdev->dev); + pm_runtime_put_sync(&timer->pdev->dev); } EXPORT_SYMBOL_GPL(omap_dm_timer_disable);