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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 5A6DCC4338F for ; Fri, 20 Aug 2021 07:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41DF661037 for ; Fri, 20 Aug 2021 07:54:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239006AbhHTHyy (ORCPT ); Fri, 20 Aug 2021 03:54:54 -0400 Received: from smtp-relay-canonical-0.canonical.com ([185.125.188.120]:60156 "EHLO smtp-relay-canonical-0.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238991AbhHTHyx (ORCPT ); Fri, 20 Aug 2021 03:54:53 -0400 Received: from localhost.localdomain (1.general.khfeng.us.vpn [10.172.68.174]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 47A893F043; Fri, 20 Aug 2021 07:54:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1629446049; bh=ywi09jLJioHV77jNrsti8DgLUfgW57ub1lXIO6DgnXE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=uqV5aOG2xgqbTjj2P+I0fnBSCRlwHzf6pdJ9jmvbO2naQtjMxX5E+X8R3J96oKVOq TM5WL3mkXHKfJZ12J4oR35UXfpN942KnL19Lt8Zh3LzLL5ErytLv1LxSwCkRUmloDj 1fmYVmTHMQ+CGM6eU21V50hrnoirR0h4ZJLlXkCuknUig/rficalZ7tgE4jgDwfLAX UV0+XlxxZznOT38DPK2phgMA00N99ASE9CEZ8GGiaXWADS2iqAxwjAuvnR5kAmG1b0 1tu2AsgjaORkqJA/nc8HyBDzQBTQyuISBKENxnmQ927CUYfYqsiBuqve+5y2VLvPV4 x3IsY/qBJawHg== From: Kai-Heng Feng To: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com Cc: Kai-Heng Feng , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , David Airlie , Daniel Vetter , Imre Deak , Uma Shankar , Manasi Navare , Ankit Nautiyal , =?UTF-8?q?Jos=C3=A9=20Roberto=20de=20Souza?= , Sean Paul , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] drm/i915/dp: Use max params for panels < eDP 1.4 Date: Fri, 20 Aug 2021 15:52:59 +0800 Message-Id: <20210820075301.693099-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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