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 03759D730B2 for ; Fri, 3 Apr 2026 19:04:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E535F10E260; Fri, 3 Apr 2026 19:03:58 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=kwiboo.se header.i=@kwiboo.se header.b="sa42E29Y"; dkim-atps=neutral Received: from smtp.forwardemail.net (smtp.forwardemail.net [121.127.44.73]) by gabe.freedesktop.org (Postfix) with ESMTPS id 459ED10E0B1 for ; Fri, 3 Apr 2026 19:03:57 +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=1775243036; bh=IrkmYXz+eQlVd/BohsNjaWpAwzykhtdCHiqXQ19+Tno=; b=sa42E29Yt4WgqHHhfEFx4nhOBCCL2068rgt3dqVqE4ocJDa2+unuxN2BZUbDexpnN7Gy/BPM2 yRrj0sPkc4sM1ebeG16OwgwIKGhHtqHRNF2YZoZxLU3LXOL4ivmAhRFv/kTE5CRsVEcO1wUrjw9 WICGYyv8GFsJlWnv/lBot/LQNnmeo9NZxPZfcuWOZ0wmApDIUUbmEeg92meJfccaRy9kRmTzIwM 9L0C1rFAEKG/kjvW1gkZ7SJC3WgaY5gQFp0PasthC8IDM68kGh3HOx/Exh5yDGoaoqFCqC+2p9T LXzv3uESbEf9zhixG8LHwVP4/zIi8qXq9bWij94A8LWg== X-Forward-Email-ID: 69d00cabdc98192b40b89309 X-Forward-Email-Sender: rfc822; jonas@kwiboo.se, smtp.forwardemail.net, 121.127.44.73 X-Forward-Email-Version: 2.6.68 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 , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Christian Hewitt , Diederik de Haas , dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Christopher Obbard Subject: [PATCH v3 01/13] drm: bridge: dw_hdmi: Disable scrambler feature when not supported Date: Fri, 3 Apr 2026 18:52:47 +0000 Message-ID: <20260403185303.80748-2-jonas@kwiboo.se> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260403185303.80748-1-jonas@kwiboo.se> References: <20260403185303.80748-1-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 --- 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 0296e110ce65..9febcb58a1df 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2133,6 +2133,8 @@ 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 */ -- 2.53.0