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=unavailable 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 D1678C4338F for ; Fri, 20 Aug 2021 17:26:28 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8B55B6103A for ; Fri, 20 Aug 2021 17:26:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8B55B6103A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 983936EAD8; Fri, 20 Aug 2021 17:26:23 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 95DCF6EAD7; Fri, 20 Aug 2021 17:26:21 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10082"; a="302399556" X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="302399556" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2021 10:26:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="463445143" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.171]) by orsmga007.jf.intel.com with SMTP; 20 Aug 2021 10:26:15 -0700 Received: by stinkbox (sSMTP sendmail emulation); Fri, 20 Aug 2021 20:26:14 +0300 Date: Fri, 20 Aug 2021 20:26:14 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Kai-Heng Feng Cc: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@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 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: <20210820075301.693099-1-kai.heng.feng@canonical.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH v3] drm/i915/dp: Use max params for panels < eDP 1.4 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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. > --- > 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