Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756533AbaGHBLF (ORCPT ); Mon, 7 Jul 2014 21:11:05 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55237 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751656AbaGGXxy (ORCPT ); Mon, 7 Jul 2014 19:53:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Vetter , Jani Nikula Subject: [PATCH 3.15 043/122] drm/i915: set backlight duty cycle after backlight enable for gen4 Date: Mon, 7 Jul 2014 16:56:45 -0700 Message-Id: <20140707235735.540523221@linuxfoundation.org> X-Mailer: git-send-email 2.0.0.254.g50f84e3 In-Reply-To: <20140707235734.234226883@linuxfoundation.org> References: <20140707235734.234226883@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jani Nikula commit 2e7eeeb59a92d09144fdb7d2dc1af77a10a7945b upstream. For reasons I can't claim to fully understand gen4 seems to require backlight duty cycle setting after the backlight has been enabled, or else black screen follows. I don't have documentation for the correct sequence on gen4 either. Confirmed on Dell Latitude D630 and MacBook4,1. This fixes a regression introduced by commit b35684b8fa94e04f55fd38bf672b737741d2f9e2 Author: Jani Nikula Date: Thu Nov 14 12:13:41 2013 +0200 drm/i915: do full backlight setup at enable time Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75791 Reported-and-tested-by: mcy@lm7.fr Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79423 Reported-and-tested-by: Marc Milgram Acked-by: Daniel Vetter Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_panel.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -723,9 +723,6 @@ static void i965_enable_backlight(struct ctl = freq << 16; I915_WRITE(BLC_PWM_CTL, ctl); - /* XXX: combine this into above write? */ - intel_panel_actually_set_backlight(connector, panel->backlight.level); - ctl2 = BLM_PIPE(pipe); if (panel->backlight.combination_mode) ctl2 |= BLM_COMBINATION_MODE; @@ -734,6 +731,8 @@ static void i965_enable_backlight(struct I915_WRITE(BLC_PWM_CTL2, ctl2); POSTING_READ(BLC_PWM_CTL2); I915_WRITE(BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE); + + intel_panel_actually_set_backlight(connector, panel->backlight.level); } static void vlv_enable_backlight(struct intel_connector *connector) -- 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/