From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from new3-smtp.messagingengine.com (new3-smtp.messagingengine.com [66.111.4.229]) (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 7B9693D6D for ; Tue, 16 Aug 2022 13:26:41 +0000 (UTC) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailnew.nyi.internal (Postfix) with ESMTP id 5CE8E5803AB; Tue, 16 Aug 2022 09:26:40 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Tue, 16 Aug 2022 09:26:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cerno.tech; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm3; t=1660656400; x=1660663600; bh=6KRBUJsiPT 0Yqq99Qd4HjijhehzFziPzaGTFO/r87og=; b=QVKXFUaEMpeOCZt8CPmRhhx4jD n3HREMCFZowMzY7fllUlDBLcOFgCk5+QnKChBKXWzj4AEqHu+UW9YmfiRMf1JPLY tnO8lVKSmY5GOZOKcu9vHCq/RxCTZ/djiE3/o1CRLDd6pG/DWZLUcsEWD3MZH+rn KGJUAZyv8MdVGcfJQF5Jz/hfTaTIb8aW1PjLZ72Zpjf1hylipdcBvOLHSSnFxMdv 2S7TOiToRua6xc+y+DD4OqVGOGbXZDkaRkYHK2K90YJl4HHbGy4YRwHiOVamT9XW nSQ8vjTaLT4xEbqWlKUenfk7G0i77ur8LuIEhrmB5Za1tZqqtATUU6e5ofrw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1660656400; x=1660663600; bh=6KRBUJsiPT0Yqq99Qd4HjijhehzF ziPzaGTFO/r87og=; b=rnH/F/tbCVxd66ER/LqD/NI4fMt6jCC3HQiaoXe71MDc fsRO2/lydPWAf9mff+RtOR4aFE2xbHRVN2ixQHawqdcfRQ8RaPuz558KXzcgLwxC vT4s0tPlOYXTG7a8/UkuLHbghD3YUHJIUnhBtDlTjIJqjxamY0/lUycST5KHtTSF MlgqPz5dZdUNX6h1YlKpywhhPqPhh8c0N4jU49vhU30WVT7NVU5sAbR0P1rRtVej 9OfivJneRSU0bVxKyA6vyjL5HugfpAfAsEBu6vG2OMWWIUgbznauiENtLblN0geb sG/Q8XjvXl0V8vW+UXiSfWErbVqF4Fpg6QIiLt0JBw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrvdehgedgieeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvfevuffkfhggtggujgesghdtreertddtvdenucfhrhhomhepofgrgihi mhgvucftihhprghrugcuoehmrgigihhmvgestggvrhhnohdrthgvtghhqeenucggtffrrg htthgvrhhnpeetfefffefgkedtfefgledugfdtjeefjedvtddtkeetieffjedvgfehheff hfevudenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe hmrgigihhmvgestggvrhhnohdrthgvtghh X-ME-Proxy: Feedback-ID: i8771445c:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 16 Aug 2022 09:26:39 -0400 (EDT) Date: Tue, 16 Aug 2022 15:26:36 +0200 From: Maxime Ripard To: Geert Uytterhoeven Cc: Jernej Skrabec , Martin Blumenstingl , Chen-Yu Tsai , Philipp Zabel , Jerome Brunet , Samuel Holland , Thomas Zimmermann , Daniel Vetter , Emma Anholt , David Airlie , Maarten Lankhorst , Noralf =?utf-8?Q?Tr=C3=B8nnes?= , Kevin Hilman , Neil Armstrong , linux-sunxi@lists.linux.dev, Linux Kernel Mailing List , Phil Elwell , Mateusz Kwiatkowski , Linux ARM , Dave Stevenson , "open list:ARM/Amlogic Meson..." , DRI Development , Dom Cobley Subject: Re: [PATCH v1 04/35] drm/modes: Introduce 480i and 576i modes Message-ID: <20220816132636.3tmwqmrox64pu3lt@houat> References: <20220728-rpi-analog-tv-properties-v1-0-3d53ae722097@cerno.tech> <20220728-rpi-analog-tv-properties-v1-4-3d53ae722097@cerno.tech> Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="2tlrvphkdkfvwysw" Content-Disposition: inline In-Reply-To: --2tlrvphkdkfvwysw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Geert, On Fri, Aug 12, 2022 at 03:18:58PM +0200, Geert Uytterhoeven wrote: > Hi Maxime, >=20 > Thanks for your patch! >=20 > On Fri, Jul 29, 2022 at 6:35 PM Maxime Ripard wrote: > > Multiple drivers (meson, vc4) define the analog TV 525-lines and 625-li= nes > > modes in the drivers. >=20 > Nit: strictly speaking these are not analog modes, but the digital > variants (ITU-R BT.656 and DVD-Video D1) of NTSC and PAL, using a > 13.5 MHz sampling frequency for pixels. >=20 > In analog modes, the only discrete values are the number of lines, and > the frame/field rate (fixing the horizontal sync rate when combined). >=20 > The number of (in)visible pixels per line depends on the available > bandwidth. In a digital variant (which is anything generated by a > digital computer system), the latter depends on the pixel clock, which > can wildly differ from the 13.5 MHz used in the BT.656 standard. (e.g. > Amiga uses 7.09/14.19/28.38 MHz (PAL) or 7.16/14.32/28.64 MHz (NTSC)). >=20 > So I think we probably need some way to generate a PAL/NTSC-compatible > mode based not only on resolution, but also on pixel clock. This would also fix the comments made by Jani and Thomas, so I quite like the idea of it. I'm struggling a bit to find how would could implement this though. =46rom what you were saying, I guess the prototype would be something like struct drm_display_mode *drm_create_analog_mode(unsigned int pixel_clock, unsigned int lines, unsigned int frame_rate) But I have zero idea on what the implementation would be. Do you have some resources for this you could point me to? Thanks Maxime --2tlrvphkdkfvwysw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCYvubDAAKCRDj7w1vZxhR xZZ+AP0f5hhgfzUf7q/FEIjfZQKIV6tN7iJX9ovg2oPpWOy6wAEA1rruwJYSqo6M knKWWD6nHN4r5wgC+HL9aAySp8ehvwE= =PTwU -----END PGP SIGNATURE----- --2tlrvphkdkfvwysw--