From patchwork Tue Jul 27 13:47:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 487056 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,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 328BDC43214 for ; Tue, 27 Jul 2021 13:49:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 165C961A8D for ; Tue, 27 Jul 2021 13:49:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237027AbhG0Ntp (ORCPT ); Tue, 27 Jul 2021 09:49:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236701AbhG0Ntj (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 C78A4C0619E3 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 aDnb2500K1fSPfK01Dnbz6; 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 1m8NQl-001Pc1-1f; Tue, 27 Jul 2021 15:47:35 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m8NQk-00FnhI-Bu; 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 2/5] video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() Date: Tue, 27 Jul 2021 15:47:27 +0200 Message-Id: <20210727134730.3765898-3-geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210727134730.3765898-1-geert@linux-m68k.org> References: <20210727134730.3765898-1-geert@linux-m68k.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Simplify the nested loops to handle conversion from linear frame buffer to ssd1307 page layout: 1. Move last page handling one level up, as the value of "m" is the same inside a page, 2. array->data[] is filled linearly, so there is no need to recalculate array_idx over and over again; a simple increment is sufficient. Signed-off-by: Geert Uytterhoeven Acked-by: Sam Ravnborg --- v2: - Add Acked-by. --- drivers/video/fbdev/ssd1307fb.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index e6b6263e3bef847f..6d7bd025bca1a175 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -158,6 +158,7 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) u8 *vmem = par->info->screen_buffer; unsigned int line_length = par->info->fix.line_length; unsigned int pages = DIV_ROUND_UP(par->height, 8); + u32 array_idx = 0; int ret, i, j, k; array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA); @@ -194,19 +195,21 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) */ for (i = 0; i < pages; i++) { + int m = 8; + + /* Last page may be partial */ + if (i + 1 == pages && par->height % 8) + m = par->height % 8; for (j = 0; j < par->width; j++) { - int m = 8; - u32 array_idx = i * par->width + j; - array->data[array_idx] = 0; - /* Last page may be partial */ - if (i + 1 == pages && par->height % 8) - m = par->height % 8; + u8 data = 0; + for (k = 0; k < m; k++) { u8 byte = vmem[(8 * i + k) * line_length + j / 8]; u8 bit = (byte >> (j % 8)) & 1; - array->data[array_idx] |= bit << k; + data |= bit << k; } + array->data[array_idx++] = data; } }