From patchwork Tue Mar 19 22:51:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 13597100 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D006FC54E71 for ; Tue, 19 Mar 2024 22:51:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1AF2910F6B5; Tue, 19 Mar 2024 22:51:46 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.b="LN8mrOGd"; dkim-atps=neutral Received: from out-176.mta0.migadu.com (out-176.mta0.migadu.com [91.218.175.176]) by gabe.freedesktop.org (Postfix) with ESMTPS id 53F4D10F6A1 for ; Tue, 19 Mar 2024 22:51:44 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710888702; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U6urapeaZnHdW/DTzeHEHFd6f+TsIuajmiHq4Eb1FjY=; b=LN8mrOGdATpuIA+XTvh2wePemRSNcyWEJNCGn+sZpgJEsunJhvJDNJukRMB2ru8j/QBufY YiswVT4xw+wAzZencVWtu2RBLy8YbBprJPHn/MNxZ8NK6uxX6ZAG+XiS+29JjbAV5jeAx8 p/T1eE95awqHrt34Vq1WgHpqYtySunE= From: Sean Anderson To: Laurent Pinchart , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel@lists.freedesktop.org Cc: Michal Simek , David Airlie , linux-kernel@vger.kernel.org, Daniel Vetter , linux-arm-kernel@lists.infradead.org, Sean Anderson Subject: [PATCH v2 3/8] drm: zynqmp_dp: Adjust training values per-lane Date: Tue, 19 Mar 2024 18:51:16 -0400 Message-Id: <20240319225122.3048400-4-sean.anderson@linux.dev> In-Reply-To: <20240319225122.3048400-1-sean.anderson@linux.dev> References: <20240319225122.3048400-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The feedback we get from the DPRX is per-lane. Make changes using this information, instead of picking the maximum values from all lanes. This results in more-consistent training on marginal links. Signed-off-by: Sean Anderson Reviewed-by: Tomi Valkeinen --- (no changes since v1) drivers/gpu/drm/xlnx/zynqmp_dp.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 98a32e6a0459..8635b5673386 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -605,28 +605,21 @@ static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp, u8 link_status[DP_LINK_STATUS_SIZE]) { u8 *train_set = dp->train_set; - u8 voltage = 0, preemphasis = 0; u8 i; for (i = 0; i < dp->mode.lane_cnt; i++) { - u8 v = drm_dp_get_adjust_request_voltage(link_status, i); - u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i); + u8 voltage = drm_dp_get_adjust_request_voltage(link_status, i); + u8 preemphasis = + drm_dp_get_adjust_request_pre_emphasis(link_status, i); - if (v > voltage) - voltage = v; + if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3) + voltage |= DP_TRAIN_MAX_SWING_REACHED; - if (p > preemphasis) - preemphasis = p; - } + if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2) + preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; - if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3) - voltage |= DP_TRAIN_MAX_SWING_REACHED; - - if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2) - preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; - - for (i = 0; i < dp->mode.lane_cnt; i++) train_set[i] = voltage | preemphasis; + } } /**