From patchwork Tue Oct 21 10:52:35 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5118661 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DB9049F349 for ; Tue, 21 Oct 2014 11:42:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0CD8220121 for ; Tue, 21 Oct 2014 11:42:46 +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 1F996200E8 for ; Tue, 21 Oct 2014 11:42:45 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id DF5CC106E; Tue, 21 Oct 2014 11:07:52 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 199BD106B for ; Tue, 21 Oct 2014 11:07:51 +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 smtp1.linuxfoundation.org (Postfix) with ESMTP id A40E8201F5 for ; Tue, 21 Oct 2014 11:07:50 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:07:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617797203" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:07:49 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:52:35 +0800 Message-Id: <1413889294-31328-556-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 0555/1094] drm/i915: get power domain in case the BIOS enabled eDP VDD 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: Paulo Zanoni If I unplug the eDP monitor, the BIOS of my machine will enable the VDD bit, then when the driver loads it will think VDD is enabled. It will detect that the eDP is not enabled and return false from intel_edp_init_connector. This will trigger a call to edp_panel_vdd_off_sync(), which trigger a WARN saying that the refcount of the power domain is less than zero. The problem happens because the driver gets a refcount whenever it enables the VDD bit, and puts the refcount whenever it disables the VDD bit. But on this case, the BIOS enabled VDD, so all we do is to call put() without calling get() first, so the code added is there to make sure we always have the get() in case the BIOS enabled the bit. This regression was introduced in commit e9cb81a22841908b1c075156b409a538d09c8466 Author: Paulo Zanoni Date: Thu Nov 21 13:47:23 2013 -0200 drm/i915: get a runtime PM reference when the panel VDD is on v2: - Rebase Tested-by: Chris Wilson (v1) Reviewed-by: Daniel Vetter Cc: stable@vger.kernel.org (v3.13+) Signed-off-by: Paulo Zanoni Signed-off-by: Jani Nikula (cherry picked from commit 636352173a0dd127636fe331c97b117a8004bf50) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/intel_dp.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index d2a5588..dfa8528 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3619,7 +3619,8 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, { struct drm_connector *connector = &intel_connector->base; struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp); - struct drm_device *dev = intel_dig_port->base.base.dev; + struct intel_encoder *intel_encoder = &intel_dig_port->base; + struct drm_device *dev = intel_encoder->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; struct drm_display_mode *fixed_mode = NULL; bool has_dpcd; @@ -3629,6 +3630,14 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, if (!is_edp(intel_dp)) return true; + /* The VDD bit needs a power domain reference, so if the bit is already + * enabled when we boot, grab this reference. */ + if (edp_have_panel_vdd(intel_dp)) { + enum intel_display_power_domain power_domain; + power_domain = intel_display_port_power_domain(intel_encoder); + intel_display_power_get(dev_priv, power_domain); + } + /* Cache DPCD and EDID for edp. */ intel_edp_panel_vdd_on(intel_dp); has_dpcd = intel_dp_get_dpcd(intel_dp);