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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50D9CC4338F for ; Tue, 27 Jul 2021 15:26:42 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C0D5A61B41 for ; Tue, 27 Jul 2021 15:26:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C0D5A61B41 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4D8A76E44A; Tue, 27 Jul 2021 15:26:41 +0000 (UTC) Received: from mx2.smtp.larsendata.com (mx2.smtp.larsendata.com [91.221.196.228]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4EAF36E44A for ; Tue, 27 Jul 2021 15:26:39 +0000 (UTC) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx2.smtp.larsendata.com (Halon) with ESMTPS id 12df8879-eeef-11eb-8d1a-0050568cd888; Tue, 27 Jul 2021 15:26:54 +0000 (UTC) Received: from ravnborg.org (80-162-45-141-cable.dk.customer.tdc.net [80.162.45.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sam@ravnborg.org) by mail01.mxhotel.dk (Postfix) with ESMTPSA id E8394194BAE; Tue, 27 Jul 2021 17:26:57 +0200 (CEST) Date: Tue, 27 Jul 2021 17:26:35 +0200 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: Geert Uytterhoeven Subject: Re: [PATCH v2 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Message-ID: References: <20210727134730.3765898-1-geert@linux-m68k.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210727134730.3765898-1-geert@linux-m68k.org> 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: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Geert, On Tue, Jul 27, 2021 at 03:47:25PM +0200, Geert Uytterhoeven wrote: > Hi all, > > This patch series optimizes console operations on ssd1307fb, after the > customary fixes and cleanups. > > Currently, each screen update triggers an I2C transfer of all screen > data, up to 1 KiB of data for a 128x64 display, which takes at least 20 > ms in Fast mode. While many displays are smaller, and thus require less > data to be transferred, 20 ms is still an optimistic value, as the > actual data transfer may be much slower, especially on bitbanged I2C > drivers. After this series, the amount of data transfer is reduced, as > fillrect, copyarea, and imageblit only update the rectangle that > changed. > > Changes compared to v1[1]: > - Add Acked-by, > - Use two separate helpers instead of a single combined helper, > - Reorder operands in DIV_ROUND_UP() to improve readability. > > This has been tested on an Adafruit FeatherWing OLED with an SSD1306 > controller and a 128x32 OLED, connected to an OrangeCrab ECP5 FPGA board > running a 64 MHz VexRiscv RISC-V softcore, where it reduced the CPU > usage for blinking the cursor from more than 70% to ca. 10%. > > Thanks for applying! Thanks for the respin - patches are now applied to drm-misc-next. Sam