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 C8311C4332F for ; Thu, 24 Nov 2022 08:56:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230009AbiKXI4P (ORCPT ); Thu, 24 Nov 2022 03:56:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230123AbiKXIzz (ORCPT ); Thu, 24 Nov 2022 03:55:55 -0500 Received: from mail-qk1-f176.google.com (mail-qk1-f176.google.com [209.85.222.176]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EA2111A72C; Thu, 24 Nov 2022 00:55:33 -0800 (PST) Received: by mail-qk1-f176.google.com with SMTP id c2so638609qko.1; Thu, 24 Nov 2022 00:55:33 -0800 (PST) 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:subject:date:message-id :reply-to; bh=ltDWhcn3gZTnH4uku4/njf53RbMuOe2j1J0ZvvamyfA=; b=N4giKjJd0Iqpf52KGNe60VWHEkJ2VmGZ/zDQA7XaBI+sh3kVt3sl7zLelG5CMZcBMC 7phZmWU/kuktXV84UoDdda3u0mgSe7MtATb/pb4aT/yJD80V/idMhHJEz0uaGoLfZ2kB m+X6keIbcybnjbnUdiutiSElfBxQsKbcvnOhlMZZfQGkdeox0ktzvx9EvbEadKaqBjD/ ZYUagPTMBwkwSWM47scOWXRpulH7s19xSp0QFOlafMZhdOpvNdXrkyy5nNIrQnbedITb rqqZ6LVPYJD04rCnae3zR32pZkM168rrgmoo/vfIqd4aj5DQwzHxCPVjtqEBVTxJKUO9 SZsA== X-Gm-Message-State: ANoB5plOx4zBuWlNj4hBdEPpc0FdnN9WEHhJDqoAbuFbro93t+kBNKbH rukMVgHiahd6OHy5sE9JYoThj0vQhRAaEg== X-Google-Smtp-Source: AA0mqf5BaMz4t/r8WDt1gqq5nATajG+kLGl1JP2BTbUwJrbQTHbL7sO0ZovhDAQvCf+DQtOArhO+eA== X-Received: by 2002:a05:620a:10b4:b0:6fb:f17e:c8f8 with SMTP id h20-20020a05620a10b400b006fbf17ec8f8mr18180106qkk.404.1669280131950; Thu, 24 Nov 2022 00:55:31 -0800 (PST) Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com. [209.85.219.174]) by smtp.gmail.com with ESMTPSA id a3-20020a05620a438300b006ce0733caebsm538159qkp.14.2022.11.24.00.55.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Nov 2022 00:55:30 -0800 (PST) Received: by mail-yb1-f174.google.com with SMTP id i131so1103715ybc.9; Thu, 24 Nov 2022 00:55:30 -0800 (PST) X-Received: by 2002:a25:9e84:0:b0:6de:6183:c5c3 with SMTP id p4-20020a259e84000000b006de6183c5c3mr12337016ybq.89.1669280130150; Thu, 24 Nov 2022 00:55:30 -0800 (PST) MIME-Version: 1.0 References: <3ee1f8144feb96c28742b22384189f1f83bcfc1a.1669221671.git.geert@linux-m68k.org> In-Reply-To: From: Geert Uytterhoeven Date: Thu, 24 Nov 2022 09:55:18 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH resend v2] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats To: Thomas Zimmermann Cc: Maarten Lankhorst , Maxime Ripard , David Airlie , Daniel Vetter , Gerd Hoffmann , linux-fbdev@vger.kernel.org, linux-m68k@lists.linux-m68k.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Thu, Nov 24, 2022 at 9:47 AM Thomas Zimmermann wrote: > Am 23.11.22 um 17:43 schrieb Geert Uytterhoeven: > > As of commit eae06120f1974e1a ("drm: refuse ADDFB2 ioctl for broken > > bigendian drivers"), drivers must set the > > quirk_addfb_prefer_host_byte_order quirk to make the drm_mode_addfb() > > compat code work correctly on big-endian machines. > > > > While that works fine for big-endian XRGB8888 and ARGB8888, which are > > mapped to the existing little-endian BGRX8888 and BGRA8888 formats, it > > does not work for big-endian XRGB1555 and RGB565, as the latter are not > > listed in the format database. > > > > Fix this by adding the missing formats. Limit this to big-endian > > platforms, as there is currently no need to support these formats on > > little-endian platforms. > > > > Fixes: 6960e6da9cec3f66 ("drm: fix drm_mode_addfb() on big endian machines.") > > Signed-off-by: Geert Uytterhoeven > > --- > > v2: > > - Use "DRM_FORMAT_foo | DRM_FORMAT_BIG_ENDIAN" instead of > > "DRM_FORMAT_HOST_foo", > > - Turn into a lone patch, as all other patches from series > > https://lore.kernel.org/r/cover.1657300532.git.geert@linux-m68k.org > > were applied to drm-misc/for-linux-next. > > --- > > drivers/gpu/drm/drm_fourcc.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c > > index e09331bb3bc73f21..265671a7f9134c1f 100644 > > --- a/drivers/gpu/drm/drm_fourcc.c > > +++ b/drivers/gpu/drm/drm_fourcc.c > > @@ -190,6 +190,10 @@ const struct drm_format_info *__drm_format_info(u32 format) > > { .format = DRM_FORMAT_BGRA5551, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true }, > > { .format = DRM_FORMAT_RGB565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > { .format = DRM_FORMAT_BGR565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > +#ifdef __BIG_ENDIAN > > + { .format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > + { .format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > Getting back to the discussion on endianess, I don't understand why the > BIG_ENDIAN flag is set here. AFAIK these formats are always little > endian. And the BE flag is set by drivers/userspace if a framebuffer > has a BE ordering. > > It would be better to filter the BE flag in __drm_format_info() before > the function does the lookup. I mentioned that alternative in [2], but rejected it because of the disadvantages: - {,__}drm_format_info() returns a pointer to a const object, whose .format field won't have the DRM_FORMAT_BIG_ENDIAN flag set, complicating callers, - All callers need to be updated, - It is difficult to know which big-endian formats are really supported, especially as only a few are needed. [2] [PATCH 1/3] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats https://lore.kernel.org/all/0744671ac096a12f0d538906bd324efa71b11400.1657300532.git.geert@linux-m68k.org 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 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 1CDA9C4332F for ; Thu, 24 Nov 2022 08:55:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 64E7510E6B4; Thu, 24 Nov 2022 08:55:36 +0000 (UTC) Received: from mail-qv1-f43.google.com (mail-qv1-f43.google.com [209.85.219.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4D50A10E6B4 for ; Thu, 24 Nov 2022 08:55:32 +0000 (UTC) Received: by mail-qv1-f43.google.com with SMTP id n12so595418qvr.11 for ; Thu, 24 Nov 2022 00:55:32 -0800 (PST) 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:subject:date:message-id :reply-to; bh=ltDWhcn3gZTnH4uku4/njf53RbMuOe2j1J0ZvvamyfA=; b=N5smQijrNtkObKpZ9ibs9Y9O1VMUuFgz6i+IC8MEqlhJXuvEqIVkBfHM3al7ROwSHL Ba4kavLUYlFbJI0LSspU2d6xmGlNtWLAqs/zjIRQ9NmzPpc+jLLschW8sazMKk0RMpLH fHZ1jTZfQRvW3IpTCM9yvs4MBOafWt35ABc5oYMRomCYQ6Hs7WS3ISTNpE7ttOMThr1T Mq6evv2qLT4pRzpXuv30WykG6tk+P42BTc3H0SooLE8vLXvL6X0P19iC5sBbE5WIS1R3 ufJ9eDc3795CbJS1y5+/MHuPwndP1ueX6Ne63PYrpBZHJgOsPyzloPiFGVK/bwrw0oBC 343A== X-Gm-Message-State: ANoB5pm5udiCfDQjQJv0L10kdspwZpHUVBwhS8yd9Y0BHbKVQO43BtDm OVWU71GZeOHa0d1OtmTZ5yA150XsSOFUUw== X-Google-Smtp-Source: AA0mqf63rXEFZldl4hvuYhJqigFmtQGxOyOdFP82W0rX9z61C6u1E4+crATh/bREK5eIvM7+PubqGA== X-Received: by 2002:a0c:ff28:0:b0:4bb:798d:879c with SMTP id x8-20020a0cff28000000b004bb798d879cmr12238212qvt.7.1669280131227; Thu, 24 Nov 2022 00:55:31 -0800 (PST) Received: from mail-yb1-f178.google.com (mail-yb1-f178.google.com. [209.85.219.178]) by smtp.gmail.com with ESMTPSA id u12-20020a05620a084c00b006ee949b8051sm520530qku.51.2022.11.24.00.55.30 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Nov 2022 00:55:30 -0800 (PST) Received: by mail-yb1-f178.google.com with SMTP id z192so1160410yba.0 for ; Thu, 24 Nov 2022 00:55:30 -0800 (PST) X-Received: by 2002:a25:9e84:0:b0:6de:6183:c5c3 with SMTP id p4-20020a259e84000000b006de6183c5c3mr12337016ybq.89.1669280130150; Thu, 24 Nov 2022 00:55:30 -0800 (PST) MIME-Version: 1.0 References: <3ee1f8144feb96c28742b22384189f1f83bcfc1a.1669221671.git.geert@linux-m68k.org> In-Reply-To: From: Geert Uytterhoeven Date: Thu, 24 Nov 2022 09:55:18 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH resend v2] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats To: Thomas Zimmermann Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Gerd Hoffmann Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Thomas, On Thu, Nov 24, 2022 at 9:47 AM Thomas Zimmermann wrote: > Am 23.11.22 um 17:43 schrieb Geert Uytterhoeven: > > As of commit eae06120f1974e1a ("drm: refuse ADDFB2 ioctl for broken > > bigendian drivers"), drivers must set the > > quirk_addfb_prefer_host_byte_order quirk to make the drm_mode_addfb() > > compat code work correctly on big-endian machines. > > > > While that works fine for big-endian XRGB8888 and ARGB8888, which are > > mapped to the existing little-endian BGRX8888 and BGRA8888 formats, it > > does not work for big-endian XRGB1555 and RGB565, as the latter are not > > listed in the format database. > > > > Fix this by adding the missing formats. Limit this to big-endian > > platforms, as there is currently no need to support these formats on > > little-endian platforms. > > > > Fixes: 6960e6da9cec3f66 ("drm: fix drm_mode_addfb() on big endian machines.") > > Signed-off-by: Geert Uytterhoeven > > --- > > v2: > > - Use "DRM_FORMAT_foo | DRM_FORMAT_BIG_ENDIAN" instead of > > "DRM_FORMAT_HOST_foo", > > - Turn into a lone patch, as all other patches from series > > https://lore.kernel.org/r/cover.1657300532.git.geert@linux-m68k.org > > were applied to drm-misc/for-linux-next. > > --- > > drivers/gpu/drm/drm_fourcc.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c > > index e09331bb3bc73f21..265671a7f9134c1f 100644 > > --- a/drivers/gpu/drm/drm_fourcc.c > > +++ b/drivers/gpu/drm/drm_fourcc.c > > @@ -190,6 +190,10 @@ const struct drm_format_info *__drm_format_info(u32 format) > > { .format = DRM_FORMAT_BGRA5551, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true }, > > { .format = DRM_FORMAT_RGB565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > { .format = DRM_FORMAT_BGR565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > +#ifdef __BIG_ENDIAN > > + { .format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > + { .format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > > Getting back to the discussion on endianess, I don't understand why the > BIG_ENDIAN flag is set here. AFAIK these formats are always little > endian. And the BE flag is set by drivers/userspace if a framebuffer > has a BE ordering. > > It would be better to filter the BE flag in __drm_format_info() before > the function does the lookup. I mentioned that alternative in [2], but rejected it because of the disadvantages: - {,__}drm_format_info() returns a pointer to a const object, whose .format field won't have the DRM_FORMAT_BIG_ENDIAN flag set, complicating callers, - All callers need to be updated, - It is difficult to know which big-endian formats are really supported, especially as only a few are needed. [2] [PATCH 1/3] drm/fourcc: Add missing big-endian XRGB1555 and RGB565 formats https://lore.kernel.org/all/0744671ac096a12f0d538906bd324efa71b11400.1657300532.git.geert@linux-m68k.org 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