From patchwork Tue Oct 21 10:58:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5122391 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9AE0DC11AC for ; Tue, 21 Oct 2014 12:08:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 958A020109 for ; Tue, 21 Oct 2014 12:08:29 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7008E200E0 for ; Tue, 21 Oct 2014 12:08:28 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 7B9A214A7; Tue, 21 Oct 2014 11:14:27 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp2.linuxfoundation.org (smtp2.linux-foundation.org [172.17.192.36]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 0E87DCFE for ; Tue, 21 Oct 2014 11:14:22 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp2.linuxfoundation.org (Postfix) with ESMTP id B30091DCCA for ; Tue, 21 Oct 2014 11:14:21 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:14:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617801015" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:14:20 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:58:23 +0800 Message-Id: <1413889294-31328-904-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 Subject: [LTSI-dev] [PATCH 0903/1094] drm/crtc-helper: skip locking checks in panicking path X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sergei Antonov Skip locking checks in drm_helper_*_in_use() if they are called in panicking path. See similar code in drm_warn_on_modeset_not_all_locked(). After panic information has been output, these WARN_ONs go off outputing a lot of lines and scrolling the panic information out of the screen. Here is a partial call trace showing how execution reaches them: ? drm_helper_crtc_in_use() ? __drm_helper_disable_unused_functions() ? several *_set_config functions ? drm_fb_helper_restore_fbdev_mode() Reviewed-by: Daniel Vetter Signed-off-by: Sergei Antonov Signed-off-by: Dave Airlie (cherry picked from commit ba6f582606655754d9dfbfc9dffe75dcf806f1dd) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/drm_crtc_helper.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index b110ca2..39169a8 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -29,6 +29,7 @@ * Jesse Barnes */ +#include #include #include @@ -88,7 +89,13 @@ bool drm_helper_encoder_in_use(struct drm_encoder *encoder) struct drm_connector *connector; struct drm_device *dev = encoder->dev; - WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + /* + * We can expect this mutex to be locked if we are not panicking. + * Locking is currently fubar in the panic handler. + */ + if (!oops_in_progress) + WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + list_for_each_entry(connector, &dev->mode_config.connector_list, head) if (connector->encoder == encoder) return true; @@ -112,7 +119,13 @@ bool drm_helper_crtc_in_use(struct drm_crtc *crtc) struct drm_encoder *encoder; struct drm_device *dev = crtc->dev; - WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + /* + * We can expect this mutex to be locked if we are not panicking. + * Locking is currently fubar in the panic handler. + */ + if (!oops_in_progress) + WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder)) return true;