Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752136Ab2HMKTE (ORCPT ); Mon, 13 Aug 2012 06:19:04 -0400 Received: from mga02.intel.com ([134.134.136.20]:4664 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491Ab2HMKTB (ORCPT ); Mon, 13 Aug 2012 06:19:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,759,1336374000"; d="scan'208";a="179927293" From: Jani Nikula To: maciej.rutecki@gmail.com, alferpal@gmail.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: daniel@ffwll.ch, jani.nikula@intel.com Subject: [PATCH 2/2] drm/i915: fall back to bit-banging if GMBUS fails in CRT EDID reads Date: Mon, 13 Aug 2012 13:22:35 +0300 Message-Id: <03e17075b1252d819178316c8b2a12573e59ddca.1344852255.git.jani.nikula@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: <201207271346.49259.maciej.rutecki@gmail.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3270 Lines: 100 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 --- drivers/gpu/drm/i915/intel_crt.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index bc5e2c9..80bf311 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -328,6 +328,36 @@ static bool intel_crt_detect_hotplug(struct drm_connector *connector) 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); @@ -338,7 +368,7 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector) BUG_ON(crt->base.type != INTEL_OUTPUT_ANALOG); 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); if (edid) { bool is_digital = edid->input & DRM_EDID_INPUT_DIGITAL; @@ -546,13 +576,13 @@ static int intel_crt_get_modes(struct drm_connector *connector) 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, -- 1.7.9.5 -- 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/