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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 DC3A1C43458 for ; Mon, 13 Jul 2026 10:23:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/XqQh0lm3AJBOATXu7kNooHtqL93ezgx+4Lhqm3Ipfw=; b=P7GAE8LUy+82DfvTrH3wcSDWyL Fi/v+HubrjM1ypKuoCjKnF10yChn8FrvKAwIA8AaqW+h4iM2HCWJ//CvK8k091qbwUs9XJm+aKpHo nVfpa4VNRtz1HJTCz7D4LCuwlS/WSf4uBmbKgL8hUEmrEnJOJPNAA67fPv4AwJmiDUxT9WALscpH3 gnSBd/+arrx2+4LkACf4VBT+Y6u95RsYDmlvVME01hF4J+xSBZag8zxwfaog7uBfhkodM6l0yCCAX l2WTg6C40kf+plwsqaeXbSkaeWZ1f6xTPO9sWOM2bBbEm4TDHwnGMQeb1KJzxP/JMRbHfI0alCx47 3I7/he9g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjDod-00000008s1v-0quv; Mon, 13 Jul 2026 10:23:11 +0000 Received: from bali.collaboradmins.com ([2a01:4f8:201:9162::2]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjDoW-00000008ryW-37jd; Mon, 13 Jul 2026 10:23:06 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260713_032304_969223_86FEA25B X-CRM114-Status: GOOD ( 19.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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