From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934812AbbI2Mih (ORCPT ); Tue, 29 Sep 2015 08:38:37 -0400 Received: from mga01.intel.com ([192.55.52.88]:38601 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754219AbbI2Mia (ORCPT ); Tue, 29 Sep 2015 08:38:30 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,608,1437462000"; d="scan'208";a="815268183" From: Jani Nikula To: "Huang Ying" , Jani Nikula Cc: kernel test robot , lkp@01.org, LKML , Clint Taylor , Daniel Vetter Subject: [PATCH] drm/i915: disable CPU PWM also on LPT/SPT backlight disable Date: Tue, 29 Sep 2015 15:41:48 +0300 Message-Id: <1443530508-12112-1-git-send-email-jani.nikula@intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <87y4fpmyqi.fsf@yhuang-dev.intel.com> References: <87y4fpmyqi.fsf@yhuang-dev.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Although we don't support or enable CPU PWM with LPT/SPT based systems, it may have been enabled prior to loading the driver. Disable the CPU PWM on LPT/SPT backlight disable to avoid warnings on LCPLL disable. The issue has been present on BDW since BDW enabling, but was recently introduced on HSW with commit 437b15b8017e0d946453c10794b0c5d4591cf180 Author: Jani Nikula Date: Fri Sep 4 16:55:13 2015 +0300 drm/i915: use pch backlight override on hsw too Reference: http://mid.gmane.org/87y4frhwsn.fsf@yhuang-dev.intel.com Reported-by: kernel test robot Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_panel.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index dd71e7f139e3..c9c94d05f3dd 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -731,6 +731,20 @@ static void lpt_disable_backlight(struct intel_connector *connector) intel_panel_actually_set_backlight(connector, 0); + /* + * Although we don't support or enable CPU PWM with LPT/SPT based + * systems, it may have been enabled prior to loading the + * driver. Disable to avoid warnings on LCPLL disable. + * + * This needs rework if we need to add support for CPU PWM on PCH split + * platforms. + */ + tmp = I915_READ(BLC_PWM_CPU_CTL2); + if (tmp & BLM_PWM_ENABLE) { + DRM_DEBUG_KMS("cpu backlight was enabled, disabling\n"); + I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE); + } + tmp = I915_READ(BLC_PWM_PCH_CTL1); I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE); } -- 2.1.4