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 E3682C48291 for ; Fri, 2 Feb 2024 15:24:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2BB6C10E7DD; Fri, 2 Feb 2024 15:24:02 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.b="ixo6/KIb"; dkim-atps=neutral Received: from out-184.mta1.migadu.com (out-184.mta1.migadu.com [95.215.58.184]) by gabe.freedesktop.org (Postfix) with ESMTPS id DDAC110E7DD for ; Fri, 2 Feb 2024 15:23:59 +0000 (UTC) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1706887437; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4aVZhq7FIbirPhZ1n41A8Y/v4CohpET3+Yrw3Uhku5U=; b=ixo6/KIb0+6clrNw5EHtXu8r2gG9UTTb3DZaYaDjnqX4Mb28QZm6dGE0QRTwq8rGKjnkWL NE9gd2Lob6EQGR8MgvT1T0XxGWSk6Zm7A07CJ2B5+ndMcl25SGVaddtYvUuIfcAmEmgUKo B/DthZgvkJ5kYJNDCLoO31+o3kM3NQ4= Date: Fri, 2 Feb 2024 23:23:42 +0800 MIME-Version: 1.0 Subject: Re: [v2,3/8] firmware/sysfb: Set firmware-framebuffer parent device Content-Language: en-US To: Thomas Zimmermann , javierm@redhat.com, pjones@redhat.com, deller@gmx.de, ardb@kernel.org Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org References: <20240202120140.3517-4-tzimmermann@suse.de> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Sui Jingfeng In-Reply-To: <20240202120140.3517-4-tzimmermann@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi, On 2024/2/2 19:58, Thomas Zimmermann wrote: > Set the firmware framebuffer's parent device, which usually is the > graphics hardware's physical device. Integrates the framebuffer in > the Linux device hierarchy and lets Linux handle dependencies among > devices. For example, the graphics hardware won't be suspended while > the firmware device is still active. This is a very nice benefit, I can't agree more! Because the backing memory of the firmware framebuffer occupied belongs to the graphics hardware itself. For PCIe device, the backing memory is typically the dedicated VRAM of the PCIe GPU. But there are some exceptions, for example, the gma500. But I think this can be fixed in the future, as majority(>99.9%) PCIe GPU has the a dedicated VRAM. For ARM and ARM64 platform device, the backing memory of the firmware framebuffer may located at the system RAM. It's common that the display controller is a platform device in the embedded world. So I think the sysfb_parent_dev() function can be extended to be able to works for platform device in the future.