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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 C6C02C07E95 for ; Mon, 19 Jul 2021 19:21:11 +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 5617E61006 for ; Mon, 19 Jul 2021 19:21:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5617E61006 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BF3E889C59; Mon, 19 Jul 2021 19:21:10 +0000 (UTC) Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1A46089C59 for ; Mon, 19 Jul 2021 19:21:08 +0000 (UTC) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id 7722b1a7-e8c6-11eb-9082-0050568c148b; Mon, 19 Jul 2021 19:21:06 +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 BA06E194B15; Mon, 19 Jul 2021 21:21:19 +0200 (CEST) Date: Mon, 19 Jul 2021 21:21:02 +0200 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: Geert Uytterhoeven Subject: Re: [PATCH resend 4/5] video: fbdev: ssd1307fb: Optimize screen updates Message-ID: References: <20210714145804.2530727-1-geert@linux-m68k.org> <20210714145804.2530727-5-geert@linux-m68k.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210714145804.2530727-5-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: linux-fbdev@vger.kernel.org, David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Geert, On Wed, Jul 14, 2021 at 04:58:03PM +0200, Geert Uytterhoeven wrote: > 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. > > Reduce the amount of transferred data by only updating the rectangle > that changed. Remove the call to ssd1307fb_set_address_range() during > initialization, as ssd1307fb_update_rect() now takes care of that. > > Note that for now the optimized operation is only used for fillrect, > copyarea, and imageblit, which are used by fbcon. > > Signed-off-by: Geert Uytterhoeven > --- > drivers/video/fbdev/ssd1307fb.c | 43 ++++++++++++++++++++------------- > 1 file changed, 26 insertions(+), 17 deletions(-) > > diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c > index cfa27ea0feab4f01..8e3d4be74723b9bf 100644 > --- a/drivers/video/fbdev/ssd1307fb.c > +++ b/drivers/video/fbdev/ssd1307fb.c > @@ -184,16 +184,18 @@ static int ssd1307fb_set_address_range(struct ssd1307fb_par *par, u8 col_start, > return ssd1307fb_write_cmd(par->client, page_end); > } > > -static int ssd1307fb_update_display(struct ssd1307fb_par *par) > +static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x, > + unsigned int y, unsigned int width, > + unsigned int height) > { > struct ssd1307fb_array *array; > u8 *vmem = par->info->screen_buffer; > unsigned int line_length = par->info->fix.line_length; > - unsigned int pages = DIV_ROUND_UP(par->height, 8); > + unsigned int pages = DIV_ROUND_UP(height + y % 8, 8); Add () like this - at least it helps me: > + unsigned int pages = DIV_ROUND_UP((height + y) % 8, 8); > u32 array_idx = 0; > int ret, i, j, k; > > - array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA); > + array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA); > if (!array) > return -ENOMEM; > > @@ -226,13 +228,18 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) > * (5) A4 B4 C4 D4 E4 F4 G4 H4 > */ > > - for (i = 0; i < pages; i++) { > + ret = ssd1307fb_set_address_range(par, par->col_offset + x, width, > + par->page_offset + y / 8, pages); > + if (ret < 0) > + goto out_free; > + > + for (i = y / 8; i < y / 8 + pages; i++) { > int m = 8; > > /* Last page may be partial */ > - if (i + 1 == pages && par->height % 8) > + if (8 * (i + 1) > par->height) > m = par->height % 8; As before, this looks wrong to me. Sam > - for (j = 0; j < par->width; j++) { > + for (j = x; j < x + width; j++) { > u8 data = 0; > > for (k = 0; k < m; k++) { > @@ -245,11 +252,17 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) > } > } > > - ret = ssd1307fb_write_array(par->client, array, par->width * pages); > + ret = ssd1307fb_write_array(par->client, array, width * pages); > + > +out_free: > kfree(array); > return ret; > } > > +static int ssd1307fb_update_display(struct ssd1307fb_par *par) > +{ > + return ssd1307fb_update_rect(par, 0, 0, par->width, par->height); > +} > > static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, > size_t count, loff_t *ppos) > @@ -299,21 +312,24 @@ static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *r > { > struct ssd1307fb_par *par = info->par; > sys_fillrect(info, rect); > - ssd1307fb_update_display(par); > + ssd1307fb_update_rect(par, rect->dx, rect->dy, rect->width, > + rect->height); > } > > static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area) > { > struct ssd1307fb_par *par = info->par; > sys_copyarea(info, area); > - ssd1307fb_update_display(par); > + ssd1307fb_update_rect(par, area->dx, area->dy, area->width, > + area->height); > } > > static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image) > { > struct ssd1307fb_par *par = info->par; > sys_imageblit(info, image); > - ssd1307fb_update_display(par); > + ssd1307fb_update_rect(par, image->dx, image->dy, image->width, > + image->height); > } > > static const struct fb_ops ssd1307fb_ops = { > @@ -493,13 +509,6 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) > if (ret < 0) > return ret; > > - /* Set column and page range */ > - ret = ssd1307fb_set_address_range(par, par->col_offset, par->width, > - par->page_offset, > - DIV_ROUND_UP(par->height, 8)); > - if (ret < 0) > - return ret; > - > /* Clear the screen */ > ret = ssd1307fb_update_display(par); > if (ret < 0) > -- > 2.25.1