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 A8A94C433FE for ; Wed, 2 Feb 2022 09:45:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245546AbiBBJpv (ORCPT ); Wed, 2 Feb 2022 04:45:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231162AbiBBJpt (ORCPT ); Wed, 2 Feb 2022 04:45:49 -0500 Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1449CC061714; Wed, 2 Feb 2022 01:45:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tronnes.org ; s=ds202112; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=aDMiXkwi3BfC3SPPQ8t8xXhg90+eUFi719hnxoui15o=; b=AKYee4MOwBLIxJGWS2Fd5t6CKY 5bUwgpmi90bHHfELNxvmRp9fT11t3EECIoR8gYj/7pN4CTYqzdoyLtEim8611KNh7YeWS9FVd2XYs jV55GZtHBN+qFeqZUbyCUOMho19C/+3xLp3waKRqvSxwh6APVoESDgt37zgg253fLHarycQNZ0Yx+ 9/xKBiwYbfIQLHleRjOPLrFnM1oy9Qw/ZgK9P+GvHPf0v7P4/PSzy7QjoE4ZZqZUuPNyAQrQQyKIv fhXd1tHCUsh0QUaU7KxEHcLtk52Gpu8od+e043gXijMYpkWd9/xDqabWGxgzJaoJD610KaClFOVc6 Cmj8mHRg==; Received: from [2a01:799:95e:a400:cca0:57ac:c55d:a485] (port=49944) by smtp.domeneshop.no with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nFCCw-00049C-ED; Wed, 02 Feb 2022 10:45:46 +0100 Message-ID: Date: Wed, 2 Feb 2022 10:45:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 1/4] drm: Add I2C connector type To: Thomas Zimmermann , Sam Ravnborg , Javier Martinez Canillas Cc: linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, Geert Uytterhoeven , Maxime Ripard , Andy Shevchenko , Emil Velikov References: <20220131201225.2324984-1-javierm@redhat.com> <20220131201225.2324984-2-javierm@redhat.com> <4d9a56a7-da25-b411-61cc-372c6fa9011d@tronnes.org> <4966d03e-ee0c-5130-3819-05a90a8f6d06@suse.de> From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= In-Reply-To: <4966d03e-ee0c-5130-3819-05a90a8f6d06@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Den 02.02.2022 10.14, skrev Thomas Zimmermann: > Hi Noralf, > > since you're here, I'll just hijack the discussion to ask something only > semi-related. > > IIRC the gud driver doesn't update the display immediately during atomic > commits. Instead, it instructs a helper thread to do the update. What's > the rational behind this design? Is that something we should adopt for > other drivers that operate over slow buses (USB, I2C, etc)? Would this > be relevant for the ssd1307 driver? > Async flushing is only necessary on multi display setups where there's only one rendering loop for all the displays. I saw what tiny/gm12u320.c did and Hans gave me the rationale. The SPI drivers run flushing inline. Info on the gud wiki: https://github.com/notro/gud/wiki/Linux-Host-Driver#asynchronous-flushing Noralf. 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 B9036C433F5 for ; Wed, 2 Feb 2022 09:45:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E827B10E6F2; Wed, 2 Feb 2022 09:45:49 +0000 (UTC) Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id A1B0C10E721 for ; Wed, 2 Feb 2022 09:45:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tronnes.org ; s=ds202112; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=aDMiXkwi3BfC3SPPQ8t8xXhg90+eUFi719hnxoui15o=; b=AKYee4MOwBLIxJGWS2Fd5t6CKY 5bUwgpmi90bHHfELNxvmRp9fT11t3EECIoR8gYj/7pN4CTYqzdoyLtEim8611KNh7YeWS9FVd2XYs jV55GZtHBN+qFeqZUbyCUOMho19C/+3xLp3waKRqvSxwh6APVoESDgt37zgg253fLHarycQNZ0Yx+ 9/xKBiwYbfIQLHleRjOPLrFnM1oy9Qw/ZgK9P+GvHPf0v7P4/PSzy7QjoE4ZZqZUuPNyAQrQQyKIv fhXd1tHCUsh0QUaU7KxEHcLtk52Gpu8od+e043gXijMYpkWd9/xDqabWGxgzJaoJD610KaClFOVc6 Cmj8mHRg==; Received: from [2a01:799:95e:a400:cca0:57ac:c55d:a485] (port=49944) by smtp.domeneshop.no with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nFCCw-00049C-ED; Wed, 02 Feb 2022 10:45:46 +0100 Message-ID: Date: Wed, 2 Feb 2022 10:45:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 1/4] drm: Add I2C connector type To: Thomas Zimmermann , Sam Ravnborg , Javier Martinez Canillas References: <20220131201225.2324984-1-javierm@redhat.com> <20220131201225.2324984-2-javierm@redhat.com> <4d9a56a7-da25-b411-61cc-372c6fa9011d@tronnes.org> <4966d03e-ee0c-5130-3819-05a90a8f6d06@suse.de> From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= In-Reply-To: <4966d03e-ee0c-5130-3819-05a90a8f6d06@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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, David Airlie , Daniel Vetter , Emil Velikov , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Geert Uytterhoeven , Maxime Ripard , Andy Shevchenko Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Den 02.02.2022 10.14, skrev Thomas Zimmermann: > Hi Noralf, > > since you're here, I'll just hijack the discussion to ask something only > semi-related. > > IIRC the gud driver doesn't update the display immediately during atomic > commits. Instead, it instructs a helper thread to do the update. What's > the rational behind this design? Is that something we should adopt for > other drivers that operate over slow buses (USB, I2C, etc)? Would this > be relevant for the ssd1307 driver? > Async flushing is only necessary on multi display setups where there's only one rendering loop for all the displays. I saw what tiny/gm12u320.c did and Hans gave me the rationale. The SPI drivers run flushing inline. Info on the gud wiki: https://github.com/notro/gud/wiki/Linux-Host-Driver#asynchronous-flushing Noralf.