From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E77BDEED6 for ; Wed, 26 Mar 2025 05:33:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742967221; cv=none; b=Cjj2AF9Hes3NE9G6oe7uhRVog9INTuRJkmwb2xAnesp55J8WTlgaA6SqMkuet55paBDGdLLUbNEQPr1TIyINhH9ON+8SF0/q0HhejxvDFR3AEVimJqexu3Vtbt3ai2ZVtWjjxTzrytOPole94FNUmkvAhFGcoYgZ/fUt1RC+JFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742967221; c=relaxed/simple; bh=ZtkHl+byYB3jXFUMZpEX6J8Zkg1NiuvJsQL2tkaY504=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=WXK+XuUTTz5PplUUNhZS0hy/B6kermox0J43xRWXcKFSefXi2JvAevapqZGKURFabLRdh/GLtNm8FiMGM3IFM8LhHEdzH33WPCVzRvTsZK32kA5GBMYCL3SOuaNroVa7WNdpMcMRDgWXQyBMJScr2UzDrgkNriqo53uoxvM2J0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Fd7mJaRk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Fd7mJaRk" Received: by smtp.kernel.org (Postfix) with ESMTPS id 3F5EAC4CEED; Wed, 26 Mar 2025 05:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742967220; bh=ZtkHl+byYB3jXFUMZpEX6J8Zkg1NiuvJsQL2tkaY504=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=Fd7mJaRkk+1OuJkqrXeCV8v8YC2vIleN2nHIAUodmuF3EPgDiYAVrjsavRPz7hVwx roEpIc8ZKIO3d6SczFhMjQneab5s3zJJ1yq/TIB2EOlbJHPWQxLbMW3ue9k0QaN/iF G2a4KY1h/UPsVf2pG+4sCW/g1zlsIcDxtFoJp/9OHYx5ozyK8j1RXh0+N3ZOV1yDe9 KImsVTClKDQIhA0uaBdUKpp8+Q1U7N7qpQhOiGNqFZ+Z81KOthkUJg3w0qvI5kPe/y oTXyWpchBxEnuApHWrzWsdKYICqiwIRM8nRfgSlIZZZ9V44mg108Q2Lm0ZUCH1IdJc mJ4ALY99MIutg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D7F4C3600D; Wed, 26 Mar 2025 05:33:40 +0000 (UTC) From: Hermes Wu via B4 Relay Date: Wed, 26 Mar 2025 13:34:13 +0800 Subject: [PATCH v2 1/5] drm/bridge: it6505: fix link training state HW register reset Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250326-fix-link-training-v2-1-756c8306f500@ite.com.tw> References: <20250326-fix-link-training-v2-0-756c8306f500@ite.com.tw> In-Reply-To: <20250326-fix-link-training-v2-0-756c8306f500@ite.com.tw> To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Pet.Weng@ite.com.tw, Kenneth.Hung@ite.com.tw, treapking@chromium.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Hermes Wu X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1742967277; l=1417; i=Hermes.wu@ite.com.tw; s=20241230; h=from:subject:message-id; bh=OPKp1zu9zQb8F0T0g3XsULli11ufIoTr8/+5pxJA4Ms=; b=fVQ4Yl7k7aszXn5kMllRwvUFeiv9cHjn5Uzo5eB3T6/HhKUoNRAwLaVs//fgI4xMDMhaNBCfR RlM35DmSu5jCqZnXvFVhjZadhD9oHlKaFrv/FwMKzNm5OLQNjpgLZtM X-Developer-Key: i=Hermes.wu@ite.com.tw; a=ed25519; pk=qho5Dawp2WWj9CGyjtJ6/Y10xH8odjRdS6SXDaDAerU= X-Endpoint-Received: by B4 Relay for Hermes.wu@ite.com.tw/20241230 with auth_id=310 X-Original-From: Hermes Wu Reply-To: Hermes.wu@ite.com.tw From: Hermes Wu In order to reset HW link auto training state, bits FORCE_RETRAIN and MANUAL_TRAIN at REG_TRAIN_CTRL1 must be set at the same time. Signed-off-by: Hermes Wu --- drivers/gpu/drm/bridge/ite-it6505.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index 88ef76a37fe6accacdd343839ff2569b31b18ceb..b47042dc06bb1e1dfd92bc0dc6d69dc918a140ba 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -1806,7 +1806,9 @@ static bool it6505_link_start_auto_train(struct it6505 *it6505) mutex_lock(&it6505->aux_lock); it6505_set_bits(it6505, REG_TRAIN_CTRL0, FORCE_CR_DONE | FORCE_EQ_DONE, 0x00); - it6505_write(it6505, REG_TRAIN_CTRL1, FORCE_RETRAIN); + /* reset link state machine and re start training*/ + it6505_write(it6505, REG_TRAIN_CTRL1, + FORCE_RETRAIN | MANUAL_TRAIN); it6505_write(it6505, REG_TRAIN_CTRL1, AUTO_TRAIN); while (timeout > 0) { @@ -2377,7 +2379,7 @@ static void it6505_stop_link_train(struct it6505 *it6505) { it6505->link_state = LINK_IDLE; cancel_work_sync(&it6505->link_works); - it6505_write(it6505, REG_TRAIN_CTRL1, FORCE_RETRAIN); + it6505_write(it6505, REG_TRAIN_CTRL1, FORCE_RETRAIN | MANUAL_TRAIN); } static void it6505_link_train_ok(struct it6505 *it6505) -- 2.34.1