From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030904Ab2I1TYl (ORCPT ); Fri, 28 Sep 2012 15:24:41 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:63006 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030450Ab2I1TDY (ORCPT ); Fri, 28 Sep 2012 15:03:24 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , alan@lxorguk.ukuu.org.uk, Jani Nikula , Alex Ferrando , Daniel Vetter Subject: [ 189/262] drm/i915: fall back to bit-banging if GMBUS fails in CRT EDID reads Date: Fri, 28 Sep 2012 11:51:58 -0700 Message-Id: <20120928183020.381733584@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120928182957.993484211@linuxfoundation.org> References: <20120928182957.993484211@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jani Nikula commit f1a2f5b7c5f0941d23eef0a095c0b99bf8d051e6 upstream. GMBUS was enabled over bit-banging as the default in commits: commit c3dfefa0a6d235bd465309e12f4c56ea16e71111 Author: Daniel Vetter Date: Tue Feb 14 22:37:25 2012 +0100 drm/i915: reenable gmbus on gen3+ again and commit 0fb3f969c8683505fb7323c06bf8a999a5a45a15 Author: Daniel Vetter Date: Fri Mar 2 19:38:30 2012 +0100 drm/i915: enable gmbus on gen2 Unfortunately, GMBUS seems to fail on some CRT displays. Add a bit-banging fallback to CRT EDID reads. LKML-Reference: <201207251020.47637.maciej.rutecki@gmail.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=45881 Signed-off-by: Jani Nikula Tested-by: Alex Ferrando Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_crt.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -284,6 +284,36 @@ static bool intel_crt_detect_hotplug(str return ret; } +static struct edid *intel_crt_get_edid(struct drm_connector *connector, + struct i2c_adapter *i2c) +{ + struct edid *edid; + + edid = drm_get_edid(connector, i2c); + + if (!edid && !intel_gmbus_is_forced_bit(i2c)) { + DRM_DEBUG_KMS("CRT GMBUS EDID read failed, retry using GPIO bit-banging\n"); + intel_gmbus_force_bit(i2c, true); + edid = drm_get_edid(connector, i2c); + intel_gmbus_force_bit(i2c, false); + } + + return edid; +} + +/* local version of intel_ddc_get_modes() to use intel_crt_get_edid() */ +static int intel_crt_ddc_get_modes(struct drm_connector *connector, + struct i2c_adapter *adapter) +{ + struct edid *edid; + + edid = intel_crt_get_edid(connector, adapter); + if (!edid) + return 0; + + return intel_connector_update_modes(connector, edid); +} + static bool intel_crt_detect_ddc(struct drm_connector *connector) { struct intel_crt *crt = intel_attached_crt(connector); @@ -299,7 +329,7 @@ static bool intel_crt_detect_ddc(struct struct i2c_adapter *i2c; i2c = intel_gmbus_get_adapter(dev_priv, dev_priv->crt_ddc_pin); - edid = drm_get_edid(connector, i2c); + edid = intel_crt_get_edid(connector, i2c); /* * This may be a DVI-I connector with a shared DDC * link between analog and digital outputs, so we @@ -498,13 +528,13 @@ static int intel_crt_get_modes(struct dr struct i2c_adapter *i2c; i2c = intel_gmbus_get_adapter(dev_priv, dev_priv->crt_ddc_pin); - ret = intel_ddc_get_modes(connector, i2c); + ret = intel_crt_ddc_get_modes(connector, i2c); if (ret || !IS_G4X(dev)) return ret; /* Try to probe digital port for output in DVI-I -> VGA mode. */ i2c = intel_gmbus_get_adapter(dev_priv, GMBUS_PORT_DPB); - return intel_ddc_get_modes(connector, i2c); + return intel_crt_ddc_get_modes(connector, i2c); } static int intel_crt_set_property(struct drm_connector *connector,