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=-11.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 9C67FC4338F for ; Tue, 27 Jul 2021 13:49:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81F2661A8D for ; Tue, 27 Jul 2021 13:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236836AbhG0Ntu (ORCPT ); Tue, 27 Jul 2021 09:49:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236699AbhG0Ntj (ORCPT ); Tue, 27 Jul 2021 09:49:39 -0400 Received: from xavier.telenet-ops.be (xavier.telenet-ops.be [IPv6:2a02:1800:120:4::f00:14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6C71C0619E0 for ; Tue, 27 Jul 2021 06:47:38 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:b0a9:7e88:5ca4:551a]) by xavier.telenet-ops.be with bizsmtp id aDnb250021fSPfK01Dnbz1; Tue, 27 Jul 2021 15:47:37 +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 1m8NQk-001Pbz-Ll; Tue, 27 Jul 2021 15:47:34 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m8NQk-00Fnh8-9y; Tue, 27 Jul 2021 15:47:34 +0200 From: Geert Uytterhoeven To: Sam Ravnborg , Maxime Ripard Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Date: Tue, 27 Jul 2021 15:47:25 +0200 Message-Id: <20210727134730.3765898-1-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-kernel@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. 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! [1] https://lore.kernel.org/dri-devel/20210714145804.2530727-1-geert@linux-m68k.org 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_{col,page}_range() video: fbdev: ssd1307fb: Optimize screen updates video: fbdev: ssd1307fb: Cache address ranges drivers/video/fbdev/ssd1307fb.c | 151 ++++++++++++++++++++++---------- 1 file changed, 104 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