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 40810EB64DA for ; Wed, 5 Jul 2023 09:35:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231613AbjGEJfQ (ORCPT ); Wed, 5 Jul 2023 05:35:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231616AbjGEJfP (ORCPT ); Wed, 5 Jul 2023 05:35:15 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C8921713 for ; Wed, 5 Jul 2023 02:34:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688549669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=2l0oWn80w44VFK/52z7+jyoTd7jTP9Axkcdy88qxz40=; b=Zu88lZ0XHkNjZtSSq/MId8+8oXq67YdE6bujPC3gLxrAC49UdcK7UNZmjXN2l2REJ8cPSv 6aO+UBIWP4jwAxtHHqMrj4Ss26EdqNZA6YRz3fpGMaYBcL5t5RFQL5mgozGHYo3or6GoDi eUId6WDNkX5dAsieV4m96nFoNBmmC8U= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-66-uPnVJEnaO_yIepBm2cWA0Q-1; Wed, 05 Jul 2023 05:34:28 -0400 X-MC-Unique: uPnVJEnaO_yIepBm2cWA0Q-1 Received: by mail-lf1-f69.google.com with SMTP id 2adb3069b0e04-4fb7d06a7e6so6259954e87.2 for ; Wed, 05 Jul 2023 02:34:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688549667; x=1691141667; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2l0oWn80w44VFK/52z7+jyoTd7jTP9Axkcdy88qxz40=; b=PPOYiwEQY5LgQLkzN3Ny4rXTjfZMIjunm/A0H0WLVediQ6MjK/UhDJxRZEz66oBaGP ZFK+BwA6qP0OG4u+RuOnYMHjKpRR7SIAzAEN6ERbFLKV6I1I5JlRlWdxatr78XLrtxKT vTVVv0qeZbeDv85B4uMUxRnJwTS1rNL9hHag1uzTX2TBhefBlAw7gezQqLiEyrTrtwHM 2KGerXONOK5WSdLgoLGPWi/wc4raLazOY0HrtOq79XqzTzuprGihfJGjQjKbQl57wZn8 erSrfS0P8kYTbUbreTb6symHvIb9rBCEEYYv/H/KbHvvCjx0ijp+zKpI9pdJ1AbmkOpZ o+GA== X-Gm-Message-State: ABy/qLa+mPC522FkCN6T9GTyvNcVcTrbWXrq52IaBgdJ0oh1l3cKLTGS olmr4qiSH802Q7dEWij0K4aDEYrXYxE+0upKEdJugp8HeCV9xNfDxYjTG7F1mouW2O5s0LhPP/A BFst2xdCtRPOd0O6SrpfBWMU= X-Received: by 2002:a05:6512:55c:b0:4fb:8603:f6aa with SMTP id h28-20020a056512055c00b004fb8603f6aamr10259736lfl.11.1688549667044; Wed, 05 Jul 2023 02:34:27 -0700 (PDT) X-Google-Smtp-Source: APBJJlHdHXA+Wnp6hB3dyZ6CUVofgFnsSNYOrPiwVRr8+Xhwm5qD73pR2kC2waLM/BUW1Q1QrDqlPA== X-Received: by 2002:a05:6512:55c:b0:4fb:8603:f6aa with SMTP id h28-20020a056512055c00b004fb8603f6aamr10259712lfl.11.1688549666653; Wed, 05 Jul 2023 02:34:26 -0700 (PDT) Received: from localhost (205.pool92-176-231.dynamic.orange.es. [92.176.231.205]) by smtp.gmail.com with ESMTPSA id u22-20020a05600c00d600b003faa6ce54b2sm1630439wmm.2.2023.07.05.02.34.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jul 2023 02:34:26 -0700 (PDT) From: Javier Martinez Canillas To: Thomas Zimmermann , maarten.lankhorst@linux.intel.com, mripard@kernel.org Cc: dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, linux-fbdev@vger.kernel.org, Thierry Reding , Mikko Perttunen Subject: Re: [PATCH 04/10] drm/tegra: Set fbdev flags In-Reply-To: References: <20230704160133.20261-1-tzimmermann@suse.de> <20230704160133.20261-5-tzimmermann@suse.de> <87wmzerc2s.fsf@minerva.mail-host-address-is-not-set> Date: Wed, 05 Jul 2023 11:34:25 +0200 Message-ID: <87a5war9b2.fsf@minerva.mail-host-address-is-not-set> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org Thomas Zimmermann writes: [...] >>> + info->flags |= FBINFO_VIRTFB; >> >> I see that all fbdev drivers just do: info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB >> >> Guess you are doing in two assignments to be consistent with drm_fbdev_dma.c ? >> I was just curious about the rationale for setting the flags in two steps. > > The _DEFAULT flag is really just a zero. And the other flags describe > different aspects of the framebuffer. I think it makes sense to set the > flags together with the respective state. For example, _VIRTFB is set > next to ->screen_buffer, because they belong together. > Yes, that makes sense. > _VIRTFB is currently only used in defio code at > > https://elixir.bootlin.com/linux/latest/source/drivers/video/fbdev/core/fb_defio.c#L232 > > I think the fbdev I/O helpers should also test this flag after all > drivers have been annotated correctly. For example, fb_io_read() would > WARN_ONCE if the _VIRTFB flag has been set; and fb_sys_read() would warn > if it hasn't been set. For the read helpers, it also makes sense to > WARN_ONCE if the _READS_FAST flag has not been set. > Agreed. Maybe you could add those warn (or at least info or debug?) even if not all drivers have been annotated correctly. That way people can be aware that is missing and fix if there are remaining drivers. > Best regards > Thomas > -- Best regards, Javier Martinez Canillas Core Platforms Red Hat