From nobody Mon Feb 9 03:13:46 2026 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 D949948BD58; Wed, 21 Jan 2026 13:47:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769003243; cv=pass; b=thNq2V2Ap7u70Xoa7Zb3rb+DvFJlqUZrx4UwXz/Nw+CtODs6rnEoVwdCru3D/cXegqRfY0Lo0oy24TOqBWj1gfrbTjUOW1LOV6Ki77vdQQmDjH8sh8L+CMIgY6rSjsOowLXlWUSkSoILhfQfiEYyAbDToK57QeHLDfHAfJW53MI= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769003243; c=relaxed/simple; bh=Fw46rztxhXlIflLl9DCo96v7GUozyz/juihMDMD9MWA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=I+/0dOnykK9peak/E9juX+SJGinY5qVxvB1yFeQtXoBeJg6SyaufHVKG6/oCRUSCfWni48SKTPHCxc7lVhvcjT/KMoaHM1kGkho/sRojZIahBVONZO2eEbbS3y7cXFS8k0gpPYF470y2Ivtt41LK2yHcxwMejsxwroAPdmtkL1g= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b=j5dQ2nNN; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b="j5dQ2nNN" ARC-Seal: i=1; a=rsa-sha256; t=1769003203; cv=none; d=zohomail.com; s=zohoarc; b=LRzYQjQ+N0Sq+zEWcK9qqm4MGmNgT+SaOBCecvalGWHQ+KTiLwamWIo1Lo4SLhJ8v9TCebnWr2pqknYMTOIXKvZGR/hXTuUiMLqVeJcJGnxmOibMI5SRkAGCNPDfuZf8pSm6Wh8bzGdXQ8By09Yc4xP/wARX+g1LcoqVrVFiQBU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1769003203; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=w+BU3yZcnZLVUl/l+ViGJZdk5XsNHMsU7ReIC8wTppQ=; b=gXvq/zaAqbxqJthCqG4CP7m4hqY44Fo6f4gjxq3axiB0nf55PzbPTNg2w9sn58VjgNo6Fi8No0dPPWQ59FKB/TwQ29s7Wu+rnBfNnx1C+ibfIWJd7Fp8DsfL1MlwusWUvP+VS4Io4Y/p8DEs+j0Wa92GU6lDlFu1O6iUkRYNlwY= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=nicolas.frattaroli@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1769003203; s=zohomail; d=collabora.com; i=nicolas.frattaroli@collabora.com; h=From:From:Date:Date:Subject:Subject:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id:Message-Id:References:In-Reply-To:To:To:Cc:Cc:Reply-To; bh=w+BU3yZcnZLVUl/l+ViGJZdk5XsNHMsU7ReIC8wTppQ=; b=j5dQ2nNN5C2JfW9jHGlX3/+rO4RO2GXIkYkda51r0g56jlBIiP7nE8F0I6IH3yKK QeSS1isEs41lf05wH/rGeONrjIWCUrmbMySmN9ERVZzBbcz9wTSf0/ZxGZbnMdLqdea AUgCweD6h0CTWW4TbKvDzjgkXMFvhDYzjR3npSDg= Received: by mx.zohomail.com with SMTPS id 1769003200788842.3646822079719; Wed, 21 Jan 2026 05:46:40 -0800 (PST) From: Nicolas Frattaroli Date: Wed, 21 Jan 2026 14:45:32 +0100 Subject: [PATCH v6 06/21] drm/display: hdmi-state-helper: Try subsampling in mode_valid 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: <20260121-color-format-v6-6-7b81a771cd0b@collabora.com> References: <20260121-color-format-v6-0-7b81a771cd0b@collabora.com> In-Reply-To: <20260121-color-format-v6-0-7b81a771cd0b@collabora.com> To: Harry Wentland , Leo Li , Rodrigo Siqueira , Alex Deucher , =?utf-8?q?Christian_K=C3=B6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Sandy Huang , =?utf-8?q?Heiko_St=C3=BCbner?= , Andy Yan , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , Dmitry Baryshkov , Sascha Hauer , Rob Herring , Jonathan Corbet Cc: kernel@collabora.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, linux-doc@vger.kernel.org, Nicolas Frattaroli X-Mailer: b4 0.14.3 drm_hdmi_connector_mode_valid assumes modes are only valid if they work with RGB. The reality is more complex however: YCbCr 4:2:0 chroma-subsampled modes only require half the pixel clock that the same mode would require in RGB. This leads to drm_hdmi_connector_mode_valid rejecting perfectly valid 420-only or 420-also modes. Fix this by checking whether the mode is 420-capable first. If so, then proceed by checking it with HDMI_COLORSPACE_YUV420 so long as the connector has legalized 420, otherwise error out. If the mode is not 420-capable, check with RGB as was previously always the case. Fixes: 47368ab437fd ("drm/display: hdmi: add generic mode_valid helper") Signed-off-by: Nicolas Frattaroli --- drivers/gpu/drm/display/drm_hdmi_state_helper.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/= drm/display/drm_hdmi_state_helper.c index 1ea3b9c93aa5..ceabfdb30f7a 100644 --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c @@ -898,8 +898,21 @@ drm_hdmi_connector_mode_valid(struct drm_connector *co= nnector, const struct drm_display_mode *mode) { unsigned long long clock; + enum hdmi_colorspace fmt; + + if (drm_mode_is_420_only(&connector->display_info, mode)) { + if (connector->ycbcr_420_allowed) + fmt =3D HDMI_COLORSPACE_YUV420; + else + return MODE_NO_420; + } else if (drm_mode_is_420_also(&connector->display_info, mode) && + connector->ycbcr_420_allowed) { + fmt =3D HDMI_COLORSPACE_YUV420; + } else { + fmt =3D HDMI_COLORSPACE_RGB; + } =20 - clock =3D drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB); + clock =3D drm_hdmi_compute_mode_clock(mode, 8, fmt); if (!clock) return MODE_ERROR; =20 --=20 2.52.0