From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758683AbcGKLFu (ORCPT ); Mon, 11 Jul 2016 07:05:50 -0400 Received: from lucky1.263xmail.com ([211.157.147.135]:58938 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758106AbcGKLFr (ORCPT ); Mon, 11 Jul 2016 07:05:47 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: ykk@rock-chips.com X-FST-TO: mark.yao@rock-chips.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: ykk@rock-chips.com X-UNIQUE-TAG: <61492dfc8b0e96926c6764c3049b7f85> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Yakir Yang To: Mark Yao , Heiko Stuebner , Rob Herring , Russell King , Philipp Zabel , Andy Yan Cc: David Airlie , Daniel Vetter , Kumar Gala , Zheng Yang , xhc@rock-chips.com, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Yakir Yang Subject: [PATCH v1 2/6] drm/rockchip: dw_hdmi: adjust cklvl & txlvl for RF/EMI Date: Mon, 11 Jul 2016 19:05:39 +0800 Message-Id: <1468235139-29460-1-git-send-email-ykk@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1468235079-29152-1-git-send-email-ykk@rock-chips.com> References: <1468235079-29152-1-git-send-email-ykk@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Reviewed-by: Douglas Anderson --- 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 a621118..cdb63ac 100644 --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c @@ -124,7 +124,7 @@ 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} }; -- 1.9.1