From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: [PATCH] drm/i915: check whether we actually received an edid in detect_ddc Date: Wed, 11 Jul 2012 11:47:51 +0200 Message-ID: <1342000071-25057-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f43.google.com (mail-wg0-f43.google.com [74.125.82.43]) by gabe.freedesktop.org (Postfix) with ESMTP id 562AC9E782 for ; Wed, 11 Jul 2012 02:47:54 -0700 (PDT) Received: by wgbdr1 with SMTP id dr1so701812wgb.12 for ; Wed, 11 Jul 2012 02:47:53 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Intel Graphics Development Cc: Daniel Vetter List-Id: intel-gfx@lists.freedesktop.org Somehow detect_ddc manages to fall through all checks when we think that something responds on the ddc i2c address, but the edid read failed. Fix this up by explicitly checking for this case. This fixes a regression on newer chips because since commit aaa377302b2994fcc2c66741b47da33feb489dca Author: Daniel Vetter Date: Sat Jun 16 15:30:32 2012 +0200 drm/i915/crt: Do not rely upon the HPD presence pin we use ddc detection also on hotplug capable platforms. And one of these reads all 0s for any i2c transaction if nothing is connected to the vga port. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=51900 Tested-by: Yang Guang Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_crt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 61d55d3..540561c 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -353,6 +353,9 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector) is_digital = edid->input & DRM_EDID_INPUT_DIGITAL; connector->display_info.raw_edid = NULL; kfree(edid); + } else { + DRM_DEBUG_KMS("CRT not detected via DDC:0x50 [no valid EDID found]\n"); + return false; } if (!is_digital) { -- 1.7.10