From nobody Sat Apr 4 01:34:07 2026 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA04D39C010 for ; Thu, 2 Apr 2026 09:28:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775122140; cv=none; b=GqWMawJGMYUH6lse0fE3q8rKFQYgFWB3jCUsuI/rFQrvLe1xDYfM2R6QcrcvfGbrSYy1Ri1KzrykdkEdQ7LjJ0oMkX+emwfGwWMbGXXR67kOaBwSgHJHCbnbACDLdfEiixmYFVwwvmkPxMcHStxGzTdCWbBIaL1NJhypWdgVBLU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775122140; c=relaxed/simple; bh=05H3Pzy/5L+Nd1htD9Y4GQp3HbECILuMzhfqpDhwccU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=g1hUikm8eWpbi0/yfa0CYQ0GW9Jkr7Pq4jQDbD8EAFw2eyIr/0DufESGEFHF0ol58F1IIymPX2VWbFN1uIrLYBrXxoIkDuUkepvL+a+v9mhq3LuR86989us0HcE0UMx9e+vRIwS0MOb9rUbS2IwFhwlBWQ1w00rPy5nLtyWvj2k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=gfh4Rf9k; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="gfh4Rf9k" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 18084C5997A; Thu, 2 Apr 2026 09:29:20 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id A94E65FDEB; Thu, 2 Apr 2026 09:28:48 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 69D6810451269; Thu, 2 Apr 2026 11:28:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1775122126; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=+OKVbnh4D/eet/8za6HYYuOE7r3CKZI7MjkoaZhFD+M=; b=gfh4Rf9kOlkm0cnjFhVPxI4iXOBekB0zFv6omI9j0x9T4DOq3T9Qg76VTTRSW20XmfFKZZ kZbmLA18mQMo1DQeZl+Q2hroRsDCGD2PjtuWLBuBrtR7Vc3aibiNNNlFNuh5cEHldL2rJ3 NRmemYC6aP3p6e7yLz79V0Buhpb9O2SDlj8FWioT273yi65yo4/Y2Ttd2GnFEXpqxiPmQ4 GBALxjJnsLFQKspLnjKd+TrIkr6dn/7pC7yZpn0wtgHwEB1ZnhtNihWLFSmII+piEsnkNX FF0B1Sqt9npi9tnryVgugD/exHMgjFEF6JrQCjTiAv7c5UrMK99HJHxwnNFbnw== From: Luca Ceresoli Date: Thu, 02 Apr 2026 11:26:01 +0200 Subject: [PATCH v3 06/11] drm/bridge: dw-hdmi: warn on unsupported attach combination Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260402-drm-lcdif-dbanc-v3-6-27cd247a0847@bootlin.com> References: <20260402-drm-lcdif-dbanc-v3-0-27cd247a0847@bootlin.com> In-Reply-To: <20260402-drm-lcdif-dbanc-v3-0-27cd247a0847@bootlin.com> To: Marek Vasut , Stefan Agner , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Liu Ying , Rob Herring , Saravana Kannan Cc: Damon Ding , "Kory Maincent (TI.com)" , =?utf-8?q?Herv=C3=A9_Codina?= , Hui Pu , Ian Ray , Thomas Petazzoni , dri-devel@lists.freedesktop.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Adam Ford , Alexander Stein , Christopher Obbard , Daniel Scally , Emanuele Ghidoli , Fabio Estevam , Francesco Dolcini , Frieder Schrempf , Gilles Talis , =?utf-8?q?Goran_Ra=C4=91enovi=C4=87?= , Heiko Schocher , Josua Mayer , Kieran Bingham , Marco Felsch , Martyn Welch , Oleksij Rempel , Peng Fan , Richard Hu , Shengjiu Wang , Stefan Eichenberger , Vitor Soares , Luca Ceresoli X-Mailer: b4 0.15.1 X-Last-TLS-Session-Version: TLSv1.3 dw-hdmi can operate in two different modes, depending on the platform data as set by the driver: A. hdmi->plat_data->output_port =3D 0: the HDMI output (port@1) in device tree is not used B. hdmi->plat_data->output_port =3D 1: the HDMI output (port@1) is parsed to find the next bridge Only case B is supported when the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is passed to the attach callback. Emit a warning when this is violated. Also return -EINVAL which would be returned by drm_bridge_attach() right after anyway. Reviewed-by: Liu Ying Tested-by: Martyn Welch Tested-by: Alexander Stein # TQMa8MPxL/MB= a8MPxL Tested-by: Damon Ding # rk3399 Signed-off-by: Luca Ceresoli --- Note: Returning when the warning triggers does not change the functional behaviour of this function. It is not strictly necessary in this patch but it will have to be done anyway in the following patch. --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/br= idge/synopsys/dw-hdmi.c index 0296e110ce65..ab1a6a8783cd 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2910,6 +2910,10 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *= bridge, { struct dw_hdmi *hdmi =3D bridge->driver_private; =20 + /* DRM_BRIDGE_ATTACH_NO_CONNECTOR requires a remote-endpoint to the next = bridge */ + if (WARN_ON((flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) && !hdmi->plat_data-= >output_port)) + return -EINVAL; + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) return drm_bridge_attach(encoder, hdmi->bridge.next_bridge, bridge, flags); --=20 2.53.0