From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.forwardemail.net (smtp.forwardemail.net [149.28.215.223]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF3FC38A738 for ; Mon, 18 May 2026 18:03:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=149.28.215.223 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779127424; cv=none; b=EM32Lhkz077IfqvRRAQUNzcfu5K1hDrVDBM003S00tnQcvHmJeHtcMiYePOzjld/EuNynMNhiqDY/UQjRgk4koVx+mIMDVkwyV2tXqciIHro92abRNWocpAZMttsg1Ia6IpQGcZeiq8mdYx091WFucvOgCHzI+H7mtBbbLKM3jw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779127424; c=relaxed/simple; bh=mc5qYkvHimozgFABBNS1IVGauTwWAU2kMYJZwG0KI34=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=svKmqu9fYlMdwhUF5So888fMmBy2+MRiK45G5vvc/685Ox08I+rI6zZEM4Vxe07g5Ph3IRlpr/1h37HIty7L8KESNBlJduNvgi9B3oDW8m/Xop86hZspyZ+XDlByYtDwUT8zjnQAhmdJ2Sex3gklhoSDl3kM2xVI3DzguGnr78A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kwiboo.se; spf=pass smtp.mailfrom=fe-bounces.kwiboo.se; dkim=pass (2048-bit key) header.d=kwiboo.se header.i=@kwiboo.se header.b=W6MTlGyt; arc=none smtp.client-ip=149.28.215.223 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kwiboo.se Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fe-bounces.kwiboo.se Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kwiboo.se header.i=@kwiboo.se header.b="W6MTlGyt" 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=1779127408; bh=6RF7BKuGakMjKCbN9mlVwwIB3PRUeYCX0ksZtYl9O4g=; b=W6MTlGytGV8Qqwz4+EdfZEqGZ5p9mvhyJCR8QFdf/G6w2JSwPDNrqPfIfAlnPHQDOh0xv70q+ 8wQwf+9BY/cKIgwLj/x1Q06TMPtw1dfMoCvmL1cEdoxPqbyGnT3JotaqJr4D1jjDIQKy06zacbM lz3uhX56p4+S6G7CcknlgJRq3o1QNWhrK+5jsCkuNfWR+zxPPI+V8i3ARoQvsxSn3l7SozGHrP9 bbUEHadPoO5BUjkeYxB/GK36qbVYk5pcQ+Yu37Vq1Upi+XWH2jlqavAsEYPh4msT1VXMDC0KiX4 nWQzofi4MTH/J8rvODZlwOVJpjmRsS3evsnfDCtcAzKg== X-Forward-Email-ID: 6a0b5429b84dbc72d2274daf X-Forward-Email-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 149.28.215.223 X-Forward-Email-Version: 2.8.12 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 , Luca Ceresoli , 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 v7 01/23] drm: bridge: dw_hdmi: Disable scrambler feature when not supported Date: Mon, 18 May 2026 18:01:37 +0000 Message-ID: <20260518180206.2480119-2-jonas@kwiboo.se> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260518180206.2480119-1-jonas@kwiboo.se> References: <20260518180206.2480119-1-jonas@kwiboo.se> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Tested-by: Diederik de Haas # Rock64, RockPro64, Quartz64-B Signed-off-by: Jonas Karlman --- v7: No change v6: Collect t-b tag v5: No change 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 41b3a9cfa2f5..d3e6a6562870 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