From patchwork Thu May 6 15:44:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 1475125 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FbdFT2fnhz9sWW; Fri, 7 May 2021 01:45:17 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1legBd-000602-M5; Thu, 06 May 2021 15:45:13 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1legBc-0005yw-Cf for kernel-team@lists.ubuntu.com; Thu, 06 May 2021 15:45:12 +0000 Received: from 1-171-231-169.dynamic-ip.hinet.net ([1.171.231.169] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1legBb-000514-F0 for kernel-team@lists.ubuntu.com; Thu, 06 May 2021 15:45:12 +0000 From: Kai-Heng Feng To: kernel-team@lists.ubuntu.com Subject: [H] [PATCH 2/2] UBUNTU: SAUCE: drm/i915/dp: Use slow and wide link training for everything Date: Thu, 6 May 2021 23:44:42 +0800 Message-Id: <20210506154443.874680-7-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210506154443.874680-1-kai.heng.feng@canonical.com> References: <20210506154443.874680-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" BugLink: https://bugs.launchpad.net/bugs/1925685 Screen flickers on Innolux eDP 1.3 panel when clock rate 540000 is in use. According to the panel vendor, though clock rate 540000 is advertised, but the max clock rate it really supports is 270000. Ville Syrjälä mentioned that fast and narrow also breaks some eDP 1.4 panel, so use slow and wide training for all panels to resolve the issue. User also confirmed that the new strategy doesn't introduce any regression on XPS 9380. v2: - Use slow and wide for everything. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3384 References: https://gitlab.freedesktop.org/drm/intel/-/issues/272 Signed-off-by: Kai-Heng Feng Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20210421052054.1434718-1-kai.heng.feng@canonical.com (backported from commit acca7762eb71bc05a8f28d29320d193150051f79 git://anongit.freedesktop.org/drm/drm-tip drm-tip) Signed-off-by: Kai-Heng Feng --- drivers/gpu/drm/i915/display/intel_dp.c | 59 +++---------------------- 1 file changed, 5 insertions(+), 54 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index cd09de530c1e..cea938279fcc 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2274,44 +2274,6 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp, return -EINVAL; } -/* Optimize link config in order: max bpp, min lanes, min clock */ -static int -intel_dp_compute_link_config_fast(struct intel_dp *intel_dp, - struct intel_crtc_state *pipe_config, - const struct link_config_limits *limits) -{ - const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode; - int bpp, clock, lane_count; - int mode_rate, link_clock, link_avail; - - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) { - int output_bpp = intel_dp_output_bpp(pipe_config->output_format, bpp); - - mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock, - output_bpp); - - for (lane_count = limits->min_lane_count; - lane_count <= limits->max_lane_count; - lane_count <<= 1) { - for (clock = limits->min_clock; clock <= limits->max_clock; clock++) { - link_clock = intel_dp->common_rates[clock]; - link_avail = intel_dp_max_data_rate(link_clock, - lane_count); - - if (mode_rate <= link_avail) { - pipe_config->lane_count = lane_count; - pipe_config->pipe_bpp = bpp; - pipe_config->port_clock = link_clock; - - return 0; - } - } - } - } - - return -EINVAL; -} - static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc) { int i, num_bpc; @@ -2553,22 +2515,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, intel_dp_can_bigjoiner(intel_dp)) pipe_config->bigjoiner = true; - if (intel_dp_is_edp(intel_dp)) - /* - * Optimize for fast and narrow. eDP 1.3 section 3.3 and eDP 1.4 - * section A.1: "It is recommended that the minimum number of - * lanes be used, using the minimum link rate allowed for that - * lane configuration." - * - * Note that we fall back to the max clock and lane count for eDP - * panels that fail with the fast optimal settings (see - * intel_dp->use_max_params), in which case the fast vs. wide - * choice doesn't matter. - */ - ret = intel_dp_compute_link_config_fast(intel_dp, pipe_config, &limits); - else - /* Optimize for slow and wide. */ - ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); + /* + * Optimize for slow and wide for everything, because there are some + * eDP 1.3 and 1.4 panels don't work well with fast and narrow. + */ + ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); /* enable compression if the mode doesn't fit available BW */ drm_dbg_kms(&i915->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en);