From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754720Ab3CZWoE (ORCPT ); Tue, 26 Mar 2013 18:44:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52512 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752033Ab3CZWoB (ORCPT ); Tue, 26 Mar 2013 18:44:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai , Daniel Vetter Subject: [ 36/98] Revert "drm/i915: try to train DP even harder" Date: Tue, 26 Mar 2013 15:42:25 -0700 Message-Id: <20130326224246.189369346@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130326224242.449070940@linuxfoundation.org> References: <20130326224242.449070940@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 3b4f819d5eac94ba8fe5e8c061f6dabfe8d7b22c upstream. This reverts commit 0d71068835e2610576d369d6d4cbf90e0f802a71. Not only that the commit introduces a bogus check (voltage_tries == 5 will never meet at the inserted code path), it brings the i915 driver into an endless dp-train loop on HP Z1 desktop machine with IVY+eDP. At least reverting this commit recovers the framebuffer (but X is still broken by other reasons...) Signed-off-by: Takashi Iwai Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1850,7 +1850,7 @@ intel_dp_start_link_train(struct intel_d for (i = 0; i < intel_dp->lane_count; i++) if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0) break; - if (i == intel_dp->lane_count && voltage_tries == 5) { + if (i == intel_dp->lane_count) { ++loop_tries; if (loop_tries == 5) { DRM_DEBUG_KMS("too many full retries, give up\n");