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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B98EBECAAD3 for ; Wed, 31 Aug 2022 08:22:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230496AbiHaIWb (ORCPT ); Wed, 31 Aug 2022 04:22:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230390AbiHaIWL (ORCPT ); Wed, 31 Aug 2022 04:22:11 -0400 Received: from mail-oa1-f52.google.com (mail-oa1-f52.google.com [209.85.160.52]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDD9CC6FED for ; Wed, 31 Aug 2022 01:20:49 -0700 (PDT) Received: by mail-oa1-f52.google.com with SMTP id 586e51a60fabf-11ba6e79dd1so22453307fac.12 for ; Wed, 31 Aug 2022 01:20:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=tL3Pu80GajPbXIuFp2pntr8ejcDbNLFHN+ltW3MDRBA=; b=chJsU8jivhcSNYsXVa+DgMSXCb6DoJVCBM8TXfnPpXZ3XdTVVMtmoO6bEijJ3U5fQA UWLCp6sC2KWSiU9TM80WQlQjZmhYmQ1FqeMouQFYw6FodO9bMPmftMjEJmMOhGkDu3en UpMRQtM4NGoFgQs5NvgCPtr0RGc2rT1izdZrb75fdEyTQDL3S9jWCRQw8+wDwpsZRrxF KGJ6RXEGBdeJh2sdcwvci5C9WpXazoJZvDpumCrsFTB8MaQCTPd7u9t68me6Ld1m+pi7 wHILAp9hMMx3Pgf6QGcORJD+Jm709tvWxnIGLV9C46TZCj2/z0TPKJ1fFWlGN3uKY5On 40qw== X-Gm-Message-State: ACgBeo1eQUA+6RjZpnlrxSXHcJUvTzhMnI4Ywm2miFp2Xbd6SPe3e1cM 9Swudo2OroV6SXTFgY2BW3xEB0yL6v+zLw== X-Google-Smtp-Source: AA6agR7q026XxgBpdRrFOScaBbFQ67VPyKlV9qohD3PZaz+u9+cjK9VkdB4N+r8cxK9hWnFuYU0K0g== X-Received: by 2002:a05:6870:a103:b0:11d:2441:668b with SMTP id m3-20020a056870a10300b0011d2441668bmr970892oae.263.1661934016861; Wed, 31 Aug 2022 01:20:16 -0700 (PDT) Received: from mail-ot1-f43.google.com (mail-ot1-f43.google.com. [209.85.210.43]) by smtp.gmail.com with ESMTPSA id 65-20020aca0544000000b00339befdfad0sm7299210oif.50.2022.08.31.01.20.16 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 31 Aug 2022 01:20:16 -0700 (PDT) Received: by mail-ot1-f43.google.com with SMTP id d18-20020a9d72d2000000b0063934f06268so9780160otk.0 for ; Wed, 31 Aug 2022 01:20:16 -0700 (PDT) X-Received: by 2002:a25:24b:0:b0:696:4e87:7cec with SMTP id 72-20020a25024b000000b006964e877cecmr14439821ybc.202.1661933679611; Wed, 31 Aug 2022 01:14:39 -0700 (PDT) MIME-Version: 1.0 References: <20220728-rpi-analog-tv-properties-v2-0-459522d653a7@cerno.tech> <20220728-rpi-analog-tv-properties-v2-10-459522d653a7@cerno.tech> <242d272b-5b79-986c-9aaf-64e62f6b37ff@gmail.com> In-Reply-To: <242d272b-5b79-986c-9aaf-64e62f6b37ff@gmail.com> From: Geert Uytterhoeven Date: Wed, 31 Aug 2022 10:14:28 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 10/41] drm/modes: Add a function to generate analog display modes To: Mateusz Kwiatkowski Cc: Maxime Ripard , Maxime Ripard , Ben Skeggs , David Airlie , Chen-Yu Tsai , Thomas Zimmermann , Jani Nikula , Lyude Paul , Philipp Zabel , Maarten Lankhorst , Rodrigo Vivi , Tvrtko Ursulin , Jernej Skrabec , Samuel Holland , Karol Herbst , =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= , Emma Anholt , Daniel Vetter , Joonas Lahtinen , Hans de Goede , Linux ARM , Phil Elwell , Intel Graphics Development , Dave Stevenson , DRI Development , Dom Cobley , Linux Kernel Mailing List , Nouveau Dev , linux-sunxi@lists.linux.dev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mateusz, On Wed, Aug 31, 2022 at 3:44 AM Mateusz Kwiatkowski wrote: > Wow. That's an enormous amount of effort put into this patch. > > But I'm tempted to say that this is actually overengineered quite a bit :D > Considering that there's no way to access all these calculations from user > space, and I can't imagine anybody using anything else than those standard > 480i/576i (and maybe 240p/288p) modes at 13.5 MHz any time soon... I'm not > sure if we actually need all this. We'll need it when we get an Amiga DRM driver, which will use 7/14/28 MHz pixel clocks. > But anyway, I'm not the maintainer of this subsystem, so I'm not the one to > decide. > > > +enum drm_mode_analog { > > + DRM_MODE_ANALOG_NTSC, > > + DRM_MODE_ANALOG_PAL, > > +}; > > Using "NTSC" and "PAL" to describe the 50Hz and 60Hz analog TV modes is common, > but strictly speaking a misnomer. Those are color encoding systems, and your > patchset fully supports lesser used, but standard encodings for those (e.g. > PAL-M for 60Hz and SECAM for 50Hz). I'd propose switching to some more neutral > naming scheme. Some ideas: > > - DRM_MODE_ANALOG_60_HZ / DRM_MODE_ANALOG_50_HZ (after standard refresh rate) > - DRM_MODE_ANALOG_525_LINES / DRM_MODE_ANALOG_625_LINES (after standard line > count) IMHO these are bad names, as e.g. VGA640x480@60 is also analog, using 60 Hz and 525 lines. Add "TV" to the name? > - DRM_MODE_ANALOG_JM / DRM_MODE_ANALOG_BDGHIKLN (after corresponding ITU System > Letter Designations) Or DRM_MODE_ITU_*? But given the long list of letters, this looks fragile to me. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds