From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67EC4C432BE for ; Thu, 26 Aug 2021 17:37:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E2546108F for ; Thu, 26 Aug 2021 17:37:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243238AbhHZRi0 (ORCPT ); Thu, 26 Aug 2021 13:38:26 -0400 Received: from mga14.intel.com ([192.55.52.115]:61186 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231801AbhHZRiZ (ORCPT ); Thu, 26 Aug 2021 13:38:25 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10088"; a="217520636" X-IronPort-AV: E=Sophos;i="5.84,354,1620716400"; d="scan'208";a="217520636" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2021 10:37:37 -0700 X-IronPort-AV: E=Sophos;i="5.84,354,1620716400"; d="scan'208";a="537536146" Received: from fbenmlih-mobile.amr.corp.intel.com (HELO intel.com) ([10.255.36.148]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2021 10:37:35 -0700 Date: Thu, 26 Aug 2021 13:37:34 -0400 From: Rodrigo Vivi To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Cc: Kai-Heng Feng , jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, David Airlie , Daniel Vetter , Imre Deak , Uma Shankar , Manasi Navare , Ankit Nautiyal , =?iso-8859-1?Q?Jos=E9?= Roberto de Souza , Sean Paul , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] drm/i915/dp: Use max params for panels < eDP 1.4 Message-ID: References: <20210820075301.693099-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 20, 2021 at 08:26:14PM +0300, Ville Syrjälä wrote: > On Fri, Aug 20, 2021 at 03:52:59PM +0800, Kai-Heng Feng wrote: > > Users reported that after commit 2bbd6dba84d4 ("drm/i915: Try to use > > fast+narrow link on eDP again and fall back to the old max strategy on > > failure"), the screen starts to have wobbly effect. > > > > Commit a5c936add6a2 ("drm/i915/dp: Use slow and wide link training for > > everything") doesn't help either, that means the affected eDP 1.2 panels > > only work with max params. > > > > So use max params for panels < eDP 1.4 as Windows does to solve the > > issue. > > > > v3: > > - Do the eDP rev check in intel_edp_init_dpcd() > > > > v2: > > - Check eDP 1.4 instead of DPCD 1.1 to apply max params > > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3714 > > Fixes: 2bbd6dba84d4 ("drm/i915: Try to use fast+narrow link on eDP again and fall back to the old max strategy on failure") > > Fixes: a5c936add6a2 ("drm/i915/dp: Use slow and wide link training for everything") > > Suggested-by: Ville Syrjälä > > Signed-off-by: Kai-Heng Feng > > Slapped a cc:stable on it and pushed to drm-intel-next. Thanks. Since I got a strange failure on CI_DIF_604 that I don't see on CI_DIF_603, I'm avoiding the display patches. This one and also dab1b47e57e0 ("drm/i915/dp: return proper DPRX link training result") I know, it is probably the other one, but I had to remove both patches for now and I'm not confident the CI will allow me to test with this one alone. If we have -rc8 I will check again later. Otherwise we will have to send to the stable mailing list later. > > > --- > > drivers/gpu/drm/i915/display/intel_dp.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > > index 75d4ebc669411..e0dbd35ae7bc0 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -2445,11 +2445,14 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > > */ > > if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, > > intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) == > > - sizeof(intel_dp->edp_dpcd)) > > + sizeof(intel_dp->edp_dpcd)) { > > drm_dbg_kms(&dev_priv->drm, "eDP DPCD: %*ph\n", > > (int)sizeof(intel_dp->edp_dpcd), > > intel_dp->edp_dpcd); > > > > + intel_dp->use_max_params = intel_dp->edp_dpcd[0] < DP_EDP_14; > > + } > > + > > /* > > * This has to be called after intel_dp->edp_dpcd is filled, PSR checks > > * for SET_POWER_CAPABLE bit in intel_dp->edp_dpcd[1] > > -- > > 2.32.0 > > -- > Ville Syrjälä > Intel