From patchwork Sun Sep 8 14:54:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonas Karlman X-Patchwork-Id: 13795531 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 7B78FCD4F4C for ; Sun, 8 Sep 2024 14:55:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E565910E28A; Sun, 8 Sep 2024 14:55:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="dDz0Rd+y"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [149.28.215.223]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9006D10E28B for ; Sun, 8 Sep 2024 14:55:47 +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=1725807332; bh=s4d/+ThRHSQtfU43RCtR36kOGQZWrroV7EpFOhfrkPA=; b=dDz0Rd+ysMJo7E7Mp/8ntt1o7OUMS97maozuVK800alL0C7nalo7oYo02BiBtmFvibztL0h6V 0esFL6jjvePN3SxQgMjohPvX5NV3d38QJK9IDb1i5UFay1F7LoC6+x+V1BETArYs4QwFf6nyIWD jI7G/S2TDMp46puwgyQdgt5YoEOQDJrvVGLifkIOXsbFcZGwwCGSVfzd6FaB18cA/uvmNM/uf44 A2xHypv3Vitpof6yldLNUz4pzBxitCaky3kOcq1x1LTHKyKf0UTnaAZcC483yTgP26gUqcAFV0Q nGJsENbQ/8W/7x4XwcR24/2fHGDKD8sfEHsUqXIkyv9Q== From: Jonas Karlman To: Heiko Stuebner , Sandy Huang , Andy Yan , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Diederik de Haas , dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jonas Karlman , Yakir Yang Subject: [PATCH v2 2/7] drm/rockchip: dw_hdmi: Adjust cklvl & txlvl for RF/EMI Date: Sun, 8 Sep 2024 14:54:59 +0000 Message-ID: <20240908145511.3331451-3-jonas@kwiboo.se> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240908145511.3331451-1-jonas@kwiboo.se> References: <20240908145511.3331451-1-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: 66ddbadf3c9877b459588e98 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 --- v2: No change --- 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 36cc700766fd..fc5e87285a91 100644 --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c @@ -202,7 +202,7 @@ 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} };