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 3D318CD8C9F for ; Mon, 8 Jun 2026 14:33:29 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=iugGz6M//lGt1WaaURxU6mN8ZBLqHGwXr3QAOF+fdCw=; b=p9Jy6CXnovox5odOi8ECs8yopU vDTCuQha23Gkxq3bQLcuo1YZ2PLR3OrCmaec8of6GfnJkFB6Z3vp3BRYdlQ1+vqNgeDfhg49gamN5 lk/VSTdPdNIYPz4n/2gaMSVArAjJsdjJEDy9qnNmXnqFsPlnzXRULbA6rzKNn0WQcQRaoPemhC5i+ +dkfHOs/JgufGrRJaG0njspx5tCLKJX5TG7Z0oXJKlAZuTWrcR8bIGknDeJ2EiZSgv629y7mIixSr wkZ1NCLL50MLC8HKbYbULtvgu3m51RgPXtmgQK1bAgn0ySIPbcWvOSalCyO5KGk4XRck87arf3hIW Bp5pVshQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wWb2X-00000003ldi-3mKG; Mon, 08 Jun 2026 14:33:21 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wWb2W-00000003ldP-0Q3W; Mon, 08 Jun 2026 14:33:20 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id C67E3401D4; Mon, 8 Jun 2026 14:33:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 371F31F00893; Mon, 8 Jun 2026 14:33:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780929199; bh=iugGz6M//lGt1WaaURxU6mN8ZBLqHGwXr3QAOF+fdCw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=mYVBFu6e9WWA45iSVRzpYm0svnNFfwQPHSuuXORY8vfPTaR5obncugfO9ZPjUMV3X ZyFGDfGY6c1/0KyL1RL4PT/VQwnPWHjDpMmYhGjfR+NC6kO1c/ZkvQl1xZeHsE6/RB +g0UZn7wj9o1XfE1Y89+eFVvTCESCkovpi5z6AyKBYVsvacUpFhp8kJd3i6TotlU5E HLNjChOoS5j25xG83iKaYOVMyHTofUNV1G76/icgPzQtScldgnudlyM6accRQPgY+T jHTjyf1KZevN7p8sOLmeIiw7KDy2YwIcSe5X73M8r8/hfxo0QIFGDDP5IxMMzYQk7e ycpGs0w66ROWQ== Date: Mon, 8 Jun 2026 16:33:17 +0200 From: Maxime Ripard To: Cristian Ciocaltea Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Sandy Huang , Heiko =?utf-8?Q?St=C3=BCbner?= , Andy Yan , Luca Ceresoli , Daniel Stone , kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH v6 02/22] drm/connector: Add HDMI 2.0 scrambler infrastructure Message-ID: <20260608-unbiased-fine-civet-ef81ac@houat> References: <20260520-dw-hdmi-qp-scramb-v6-0-24b74603b782@collabora.com> <20260520-dw-hdmi-qp-scramb-v6-2-24b74603b782@collabora.com> <20260521-sweet-devout-panther-44d73c@penduick> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha384; protocol="application/pgp-signature"; boundary="dz5oq2q557ojbffs" Content-Disposition: inline In-Reply-To: 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 --dz5oq2q557ojbffs Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v6 02/22] drm/connector: Add HDMI 2.0 scrambler infrastructure MIME-Version: 1.0 On Fri, May 22, 2026 at 01:57:16PM +0300, Cristian Ciocaltea wrote: > Hi Maxime, >=20 > On 5/21/26 10:52 AM, Maxime Ripard wrote: > > Hi, > >=20 > > Thanks for working on this! >=20 > Thanks for your quick review! :-) >=20 > >=20 > > On Wed, May 20, 2026 at 09:38:13PM +0300, Cristian Ciocaltea wrote: > >> Add the connector-level infrastructure to support HDMI 2.0 scrambling: > >> > >> - .scrambler_src_{enable|disable}() callbacks in > >> drm_connector_hdmi_funcs for source-side scrambling control > >> - A delayed work item (scdc_work) with an associated callback (scdc_cb) > >> for periodic monitoring of sink-side scrambling status > >> - A scrambler_enabled flag to track whether scrambling is currently > >> active > >> > >> These are intended to be used by SCDC scrambling helpers to coordinate > >> scrambling setup and teardown between the source driver and the DRM > >> core. > >> > >> Signed-off-by: Cristian Ciocaltea > >> --- > >> drivers/gpu/drm/drm_connector.c | 14 +++++++++++ > >> include/drm/drm_connector.h | 52 ++++++++++++++++++++++++++++++++= +++++++++ > >> 2 files changed, 66 insertions(+) > >=20 > > So we would need kunit tests for this. >=20 > Ack. >=20 > >=20 > >> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_con= nector.c > >> index 3fa4d2082cd7..91e58362fbc0 100644 > >> --- a/drivers/gpu/drm/drm_connector.c > >> +++ b/drivers/gpu/drm/drm_connector.c > >> @@ -220,6 +220,19 @@ void drm_connector_free_work_fn(struct work_struc= t *work) > >> } > >> } >=20 > [...] >=20 > >> + /** > >> + * @scdc_work: Work item currently used to monitor sink-side scrambl= ing > >> + * status and retry setup if the sink resets it. > >> + */ > >> + struct delayed_work scdc_work; > >> + > >> + /** @scdc_cb: Callback to be invoked as part of @scdc_work. > >> + * > >> + * Currently used to monitor sink-side scrambling status and retry > >> + * setup if the sink resets it. > >> + * > >> + * This is assigned by the framework when making use of > >> + * drm_scdc_start_scrambling() helper. > >> + */ > >> + void (*scdc_cb)(struct drm_connector *connector); > >> + > >=20 > > I'm really not sure what the monitor thing is about. If we have setup > > the scrambler at enable time, and we set it again on hotplugging, why > > would we need to monitor anything? >=20 > This is similar to 257d36d493e9 ("drm/vc4: hdmi: Add a workqueue to set > scrambling") in order to deal with some displays needing a retry on scram= bling > setup. Ah, I see, sorry :) It looks pretty generic though, should we have a helper for this then? > > Also, scrambling is only relevant for HDMI 2.0. We need a way to expose > > that somehow and make sure that HDMI 2.0 drivers actually have > > scrambling setup. >=20 > I assumed drivers that do not reject the HDMI 2.0 rates in their > .tmds_char_rate_valid() are implicitly expected to support scrambling.=20 > Thinking again we could extend the framework to provide some additional c= hecks, > but let's discuss the topic on the SCDC patch. HDMI 2.0 isn't just about scrambling though, YUV420 is another big addition, and iirc you have more audio formats too. Maxime --dz5oq2q557ojbffs Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJUEABMJAB0WIQTkHFbLp4ejekA/qfgnX84Zoj2+dgUCaibSqwAKCRAnX84Zoj2+ do7YAYCfrpxaHg3m6G+IiRqezJuRRmyQNwjovYNFLjuREFLQxghM4gMvGmE7pmAW 3hOQ6BEBfRxz2jWMK3nc4dR6/Qj1A5+0DESQ0ehAECjdv51IDnfVHM3N9dMPhRvg A81cnhvAvA== =xhk/ -----END PGP SIGNATURE----- --dz5oq2q557ojbffs--