From patchwork Sat Jun 15 17:03:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonas Karlman X-Patchwork-Id: 13699332 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 9CDE7C27C7B for ; Sat, 15 Jun 2024 17:16:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 595D210E0D7; Sat, 15 Jun 2024 17:16:21 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="AAfyi5xO"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [149.28.215.223]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8100610E280 for ; Sat, 15 Jun 2024 17:15:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kwiboo.se; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-ID: Date: Subject: Cc: To: From; q=dns/txt; s=fe-e1b5cab7be; t=1718471748; bh=edw+pFynRH27QoyX9zOhxiRHTMZh2GXeD3zDbH9aM0s=; b=AAfyi5xOU9HR7BcRNkHuvUq6LmQOg6WNpqGps4Gy9a+YUhxuJc/Jpc8OGh0poBOTFSQNWJNpF +gl29NuTC7Lg4sqvbPy74yLdRUzOL8ucBuALxT3peLCO1zpYLcyD41C1I3EJfW9NCe9R0S0IftM oTr43U5685XJ16oF60ShORYULDEzvUNcupOm6PU3OGHIvUOasYG70aU/O/sXpneRWIxcz9dSJEm kpyrA4HEqBd83oDVSGYKVPfpLSQ4Q0cyOjyYuffWF/uAYD69BFTRjsm08FyIOOgQiQjFXFVLhSo vcF7/n8WK1AB85YRDgtpwjAIqh3f7/eZ/aaMfA0D+7ZQ== From: Jonas Karlman To: dri-devel@lists.freedesktop.org, Sandy Huang , " =?utf-8?q?Heiko_St=C3=BCbner?= " , Andy Yan , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter Cc: linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Jonas Karlman , Yakir Yang Subject: [PATCH 08/13] drm/rockchip: dw_hdmi: Adjust cklvl & txlvl for RF/EMI Date: Sat, 15 Jun 2024 17:03:59 +0000 Message-ID: <20240615170417.3134517-9-jonas@kwiboo.se> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240615170417.3134517-1-jonas@kwiboo.se> References: <20240615170417.3134517-1-jonas@kwiboo.se> MIME-Version: 1.0 X-Report-Abuse-To: abuse@forwardemail.net X-Report-Abuse: abuse@forwardemail.net X-Complaints-To: abuse@forwardemail.net X-ForwardEmail-Version: 0.4.40 X-ForwardEmail-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 149.28.215.223 X-ForwardEmail-ID: 666dc9bc24e0254b39804063 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" From: Yakir Yang Dut to the high HDMI signal voltage driver, Mickey have meet a serious RF/EMI problem, so we decided to reduce HDMI signal voltage to a proper value. The default params for phy is cklvl = 20 & txlvl = 13 (RF/EMI failed) ck: lvl = 13, term=100, vlo = 2.71, vhi=3.14, vswing = 0.43 tx: lvl = 20, term=100, vlo = 2.81, vhi=3.16, vswing = 0.35 1. We decided to reduce voltage value to lower, but VSwing still keep high, RF/EMI have been improved but still failed. ck: lvl = 6, term=100, vlo = 2.61, vhi=3.11, vswing = 0.50 tx: lvl = 6, term=100, vlo = 2.61, vhi=3.11, vswing = 0.50 2. We try to keep voltage value and vswing both lower, then RF/EMI test all passed ;) ck: lvl = 11, term= 66, vlo = 2.68, vhi=3.09, vswing = 0.40 tx: lvl = 11, term= 66, vlo = 2.68, vhi=3.09, vswing = 0.40 When we back to run HDMI different test and single-end test, we see different test passed, but signle-end test failed. The oscilloscope show that simgle-end clock's VL value is 1.78v (which remind LowLimit should not lower then 2.6v). 3. That's to say there are some different between PHY document and measure value. And according to experiment 2 results, we need to higher clock voltage and lower data voltage, then we can keep RF/EMI satisfied and single-end & differen test passed. ck: lvl = 9, term=100, vlo = 2.65, vhi=3.12, vswing = 0.47 tx: lvl = 16, term=100, vlo = 2.75, vhi=3.15, vswing = 0.39 Signed-off-by: Yakir Yang Signed-off-by: Jonas Karlman --- drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c index 4acf73b5692a..205cfe02079f 100644 --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c @@ -204,7 +204,7 @@ static const struct dw_hdmi_curr_ctrl rockchip_cur_ctr[] = { static const struct dw_hdmi_phy_config rockchip_phy_config[] = { /*pixelclk symbol term vlev*/ { 74250000, 0x8009, 0x0004, 0x0272}, - { 148500000, 0x802b, 0x0004, 0x028d}, + { 165000000, 0x802b, 0x0004, 0x0209}, { 297000000, 0x8039, 0x0005, 0x028d}, { ~0UL, 0x0000, 0x0000, 0x0000} };