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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 90657C43460 for ; Tue, 18 May 2021 09:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7558160720 for ; Tue, 18 May 2021 09:06:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347716AbhERJHd (ORCPT ); Tue, 18 May 2021 05:07:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347717AbhERJHP (ORCPT ); Tue, 18 May 2021 05:07:15 -0400 Received: from andre.telenet-ops.be (andre.telenet-ops.be [IPv6:2a02:1800:120:4::f00:15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7DA1C06138C for ; Tue, 18 May 2021 02:05:56 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:c161:a89e:52bd:1787]) by andre.telenet-ops.be with bizsmtp id 695s2500U446CkP0195sSH; Tue, 18 May 2021 11:05:52 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1livfk-006q2F-2z; Tue, 18 May 2021 11:05:52 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1liv5J-0069n1-Kq; Tue, 18 May 2021 10:28:13 +0200 From: Geert Uytterhoeven To: Maxime Ripard , David Airlie , Daniel Vetter Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Date: Tue, 18 May 2021 10:28:04 +0200 Message-Id: <20210518082809.1467549-1-geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org 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. 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 your comments! Geert Uytterhoeven (5): video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range() video: fbdev: ssd1307fb: Optimize screen updates video: fbdev: ssd1307fb: Cache address ranges drivers/video/fbdev/ssd1307fb.c | 143 +++++++++++++++++++++----------- 1 file changed, 96 insertions(+), 47 deletions(-) -- 2.25.1 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