From mboxrd@z Thu Jan 1 00:00:00 1970 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 9363EFF885A for ; Mon, 4 May 2026 19:11:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E656910E825; Mon, 4 May 2026 19:11:27 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="OFnDXBCQ"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [149.28.215.223]) by gabe.freedesktop.org (Postfix) with ESMTPS id BC51D10E825 for ; Mon, 4 May 2026 19:11:25 +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=1777921884; bh=NVWUpLoYoqwHrhK1PEs6caGhSJc5nSsIxxdrR4kmbpQ=; b=OFnDXBCQWjMoMZSfaPn74NSQD2wQMZoFPGVnXIpFGPq/bHtZ9rnPv2mGjR6F3W8kwU5+Vb64o c1pDq8wml9w3y0mFONrnn/JAV/fi6832IC2oW2S4zxJG9VkxTGlyu2iTyEPTG1YBIeSox+Ls+0N hlypy33v4T7eS3EARRoaY6Rwlga1UdJzDkxSlyRAAnb1PRbXlvqzS35C2FdMasVmOJZOMXhSJ6E xqSDpXLAtPKlnN8nlT3kDSwUzpo7xjCFKvRPic1wOaLiod4ySfBuSbd2YeiXrYu356ztxE1JLML w8GZpBkiM2/xcnIUi3ko7VfbDerXeOmsoipA2bwaZJbA== X-Forward-Email-ID: 69f8ef4e04bb1dff846bb7fb X-Forward-Email-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 149.28.215.223 X-Forward-Email-Version: 2.7.7 X-Forward-Email-Website: https://forwardemail.net X-Complaints-To: abuse@forwardemail.net X-Report-Abuse: abuse@forwardemail.net X-Report-Abuse-To: abuse@forwardemail.net From: Jonas Karlman To: Andrzej Hajda , Neil Armstrong , Robert Foss , Heiko Stuebner , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Liu Ying , Sandy Huang , Andy Yan , Chen-Yu Tsai , Christian Hewitt , Diederik de Haas , Nicolas Frattaroli , Dmitry Baryshkov , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-sunxi@lists.linux.dev, imx@lists.linux.dev, linux-kernel@vger.kernel.org, Christopher Obbard Subject: [PATCH v4 01/17] drm: bridge: dw_hdmi: Disable scrambler feature when not supported Date: Mon, 4 May 2026 19:10:38 +0000 Message-ID: <20260504191059.275928-2-jonas@kwiboo.se> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260504191059.275928-1-jonas@kwiboo.se> References: <20260504191059.275928-1-jonas@kwiboo.se> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 scrambler feature can be left enabled when hotplugging from a sink and mode that require scrambling to a sink that does not support SCDC or scrambling. Typically a blank screen or 'no signal' message can be observed after using a HDMI 2.0 4K@60Hz mode and then hotplugging to a sink that only support HDMI 1.4. Fix this by disabling the scrambler feature when SCDC is not supported. Fixes: 264fce6cc2c1 ("drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support") Reported-by: Christopher Obbard Reviewed-by: Neil Armstrong Signed-off-by: Jonas Karlman --- v4: No change v3: Collect r-b tag v2: New patch --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index f4a1ebb79716..248454c45d6b 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2135,6 +2135,8 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi, HDMI_MC_SWRSTZ); drm_scdc_set_scrambling(hdmi->curr_conn, 0); } + } else if (hdmi->version >= 0x200a) { + hdmi_writeb(hdmi, 0, HDMI_FC_SCRAMBLER_CTRL); } /* Set up horizontal active pixel width */ -- 2.54.0