Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752222Ab2HKG4q (ORCPT ); Sat, 11 Aug 2012 02:56:46 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57975 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767Ab2HKG4p (ORCPT ); Sat, 11 Aug 2012 02:56:45 -0400 Date: Sat, 11 Aug 2012 08:56:42 +0200 Message-ID: From: Takashi Iwai To: Daniel Vetter Cc: Hugh Dickins , Linus Torvalds , Chris Wilson , Giacomo Comes , Paulo Zanoni , linux-kernel@vger.kernel.org Subject: [PATCH v2] drm/i915: Fix blank panel at reopening lid In-Reply-To: References: User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.1 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2197 Lines: 62 When you reopen the lid on a laptop with PCH, the panel suddenly goes blank sometimes. It seems because BLC_PWM_CPU_CTL register is cleared to zero when BLC_PWM_CPU_CTL2 and BLC_PWM_PCH_CTL1 registers are enabled. This patch fixes the problem by moving the call of the function setting BLC_PWM_CPU_CTL after enabling other two registers. Reported-and-tested-by: Hugh Dickins Signed-off-by: Takashi Iwai --- v1->v2: add comments, fixed changelog drivers/gpu/drm/i915/intel_panel.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 10c7d39..d564c05 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -311,9 +311,6 @@ void intel_panel_enable_backlight(struct drm_device *dev, if (dev_priv->backlight_level == 0) dev_priv->backlight_level = intel_panel_get_max_backlight(dev); - dev_priv->backlight_enabled = true; - intel_panel_actually_set_backlight(dev, dev_priv->backlight_level); - if (INTEL_INFO(dev)->gen >= 4) { uint32_t reg, tmp; @@ -326,7 +323,7 @@ void intel_panel_enable_backlight(struct drm_device *dev, * we don't track the backlight dpms state, hence check whether * we have to do anything first. */ if (tmp & BLM_PWM_ENABLE) - return; + goto set_level; if (dev_priv->num_pipe == 3) tmp &= ~BLM_PIPE_SELECT_IVB; @@ -347,6 +344,14 @@ void intel_panel_enable_backlight(struct drm_device *dev, I915_WRITE(BLC_PWM_PCH_CTL1, tmp); } } + +set_level: + /* Call below after setting BLC_PWM_CPU_CTL2 and BLC_PWM_PCH_CTL1. + * BLC_PWM_CPU_CTL may be cleared to zero automatically when these + * registers are set. + */ + dev_priv->backlight_enabled = true; + intel_panel_actually_set_backlight(dev, dev_priv->backlight_level); } static void intel_panel_init_backlight(struct drm_device *dev) -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/