From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 35DEE3E639D for ; Mon, 13 Jul 2026 10:23:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783938188; cv=none; b=MVtoYfio8fB/BIOwsjmMHv0WVvhWp4XgedDK4skEoB8GDA8C+ivedRqb1gdv87d5b/wUFz9aGMyFSoKZXvtbUdqZALL2hYhG0vBEDZjx3/VcQMADUKKS6AJSgeWVyptSoM23gK7Mbico/9MTEgaNMpEF/cgLsyTANZEoBrRHHqs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783938188; c=relaxed/simple; bh=2r583XFfObOO9iTa1b+fiv9AEByaQ06sNo4m0E6ODtM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HbNzl+qWwh49zhT1POf9QuY02W/+vi0OrwiDTaSd6TyoVxEUm3vuaPoYQKxg/Z6CuL7w2Bt2gqrvaxROPu21YbQhgIpWL6usT72IpCQTUQRG+64U/Nla09oZZTBtwn7yddpqoPSNcIV5504WJiKzAYX45yoQ6i/JJrqwV0EXSdM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=NZb6XZ//; arc=none smtp.client-ip=148.251.105.195 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 (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="NZb6XZ//" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1783938182; bh=2r583XFfObOO9iTa1b+fiv9AEByaQ06sNo4m0E6ODtM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=NZb6XZ//5JX0tOhJA7XAYNQcOl8FFLopCWT74GVz3uGNrs+oaysIKDUILbXHolj+l U+mXStLMVirMzQviZqKZdgRuZquMmdUmTRhmnSi6PtHnXAl1JTEfnLFS57pAH/SBnR 30ki5UfRzkg1XBOZPkJzntRo2UZ94AEu9cHDdXypFjbbY2pI0EIbCtPKMuJxIuHqKN ewK6lzPzuebILhrYvY8M82B++JGnIgeXbY6Mzp5hr7q2zQG59hBMwTDpIaHxOcJ0YC Kz4su9gynjYJwiTYM1VPdRigw/pfrLyGO2jTFwg0CYakYgC39zNYlkEX88Jfhufu0/ 4dQY1Nt2JIHOg== Received: from [100.64.0.241] (unknown [100.64.0.241]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id 4DB7C17E03CE; Mon, 13 Jul 2026 12:23:01 +0200 (CEST) Message-ID: <91c3a825-3344-4ff5-8ea0-f8f057665b3f@collabora.com> Date: Mon, 13 Jul 2026 13:23:00 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 04/39] drm/connector: Add HDMI 2.0 scrambler infrastructure To: Maxime Ripard Cc: Dmitry Baryshkov , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Sandy Huang , =?UTF-8?Q?Heiko_St=C3=BCbner?= , Andy Yan , Daniel Stone , Dave Stevenson , =?UTF-8?Q?Ma=C3=ADra_Canal?= , Raspberry Pi Kernel Maintenance , kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org References: <20260702-dw-hdmi-qp-scramb-v8-0-d79890d00b6a@collabora.com> <20260702-dw-hdmi-qp-scramb-v8-4-d79890d00b6a@collabora.com> <17753a1c-824a-4835-ac2d-8b2796bba1eb@collabora.com> <534b921c-638c-4fc3-b89e-5dfc1f269f96@collabora.com> <20260713-statuesque-nonchalant-seagull-b9c39d@houat> Content-Language: en-US From: Cristian Ciocaltea In-Reply-To: <20260713-statuesque-nonchalant-seagull-b9c39d@houat> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/13/26 11:50 AM, Maxime Ripard wrote: > On Thu, Jul 09, 2026 at 10:25:54PM +0300, Cristian Ciocaltea wrote: >> On 7/3/26 11:54 PM, Cristian Ciocaltea wrote: >>> On 7/3/26 5:34 PM, Dmitry Baryshkov wrote: >>>> On Thu, Jul 02, 2026 at 05:46:17PM +0300, Cristian Ciocaltea wrote: >>>>> Add the connector-level infrastructure to support HDMI 2.0 scrambling: >>>>> >>>>> - A scrambler_supported flag to indicate whether the source supports the >>>>> scrambling capability, in which case the newly introduced >>>>> .scrambler_{enable|disable}() callbacks in drm_connector_hdmi_funcs >>>>> are mandatory >>>> >>>> Do we need a flag? What would it mean if the flag is set, but the >>>> callbacks are not? Can we drop the flag and use the presence of the >>>> callbacks as a way to identify that scrambler is enabled? >>> >>> The flag is intended to be set only within drmm_connector_hdmi_init_with_caps() >>> when drivers advertise HDMI 2.x capability, in which case it also ensures the >>> callbacks are provided. >>> >>> We could drop the flag and instead have the init helper clear the callbacks if >>> they were provided for HDMI 1.x. This might slightly reduce code readability, >>> as it relies on checking the presence of individual callbacks - especially since >>> we plan to extend this further with HDMI 2.1 support, providing four or five >>> additional FRL-specific callbacks. >> >> I tried to replace the flag with a helper that checks the presence of (one of) >> the callbacks, but it's not straightforward to unset those for non-HDMI 2.x >> cases since the hdmi_funcs argument is immutable. > > I'm not sure why we would need to unset them. If the driver states that > it support HDMI 2.0, then it needs to be there, if it doesn't, then who > cares? it's not going to be used. We can log a warning that it's > inconsistent I guess, but there's no need to actively remove it. I was trying to address the use case where drivers provide the scrambler callbacks despite not supporting HDMI 2.0. If we replace the scrambler_supported flag with a helper checking the presence of the scrambler callbacks, then we would need to ensure the callbacks do not exist in this case. Since we cannot/don't want to unset them, the remaining solution would be to bail out in init(). >> Also, rejecting that use case is less than ideal, since we would restrict >> reusing the struct instance, e.g. to support HW revisions with varying >> scrambling capabilities. > > We can have several structures instances in that case. Fair enough, I wasn't sure if that'd be an acceptable drawback. Thanks, Cristian