From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932363AbcEXSGz (ORCPT ); Tue, 24 May 2016 14:06:55 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37881 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964965AbcEXRzu (ORCPT ); Tue, 24 May 2016 13:55:50 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Chris Wilson , Maarten Lankhorst , Daniel Vetter , Daniel Vetter , Jani Nikula , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 14/53] drm/i915: Bail out of pipe config compute loop on LPT Date: Tue, 24 May 2016 10:54:44 -0700 Message-Id: <1464112523-3701-15-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1464112523-3701-1-git-send-email-kamal@canonical.com> References: <1464112523-3701-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt11 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Daniel Vetter commit 2700818ac9f935d8590715eecd7e8cadbca552b6 upstream. LPT is pch, so might run into the fdi bandwidth constraint (especially since it has only 2 lanes). But right now we just force pipe_bpp back to 24, resulting in a nice loop (which we bail out with a loud WARN_ON). Fix this. Cc: Chris Wilson Cc: Maarten Lankhorst References: https://bugs.freedesktop.org/show_bug.cgi?id=93477 Signed-off-by: Daniel Vetter Tested-by: Chris Wilson Signed-off-by: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1462264381-7573-1-git-send-email-daniel.vetter@ffwll.ch (cherry picked from commit f58a1acc7e4a1f37d26124ce4c875c647fbcc61f) Signed-off-by: Jani Nikula Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/i915/intel_crt.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 521af2c..1b34f00 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -320,8 +320,14 @@ static bool intel_crt_compute_config(struct intel_encoder *encoder, pipe_config->has_pch_encoder = true; /* LPT FDI RX only supports 8bpc. */ - if (HAS_PCH_LPT(dev)) + if (HAS_PCH_LPT(dev)) { + if (pipe_config->bw_constrained && pipe_config->pipe_bpp < 24) { + DRM_DEBUG_KMS("LPT only supports 24bpp\n"); + return false; + } + pipe_config->pipe_bpp = 24; + } /* FDI must always be 2.7 GHz */ if (HAS_DDI(dev)) { -- 2.7.4