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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12E4DC43217 for ; Tue, 8 Feb 2022 15:23:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380044AbiBHPXo (ORCPT ); Tue, 8 Feb 2022 10:23:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351682AbiBHPXn (ORCPT ); Tue, 8 Feb 2022 10:23:43 -0500 Received: from mail-ua1-f44.google.com (mail-ua1-f44.google.com [209.85.222.44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6469C061576; Tue, 8 Feb 2022 07:23:42 -0800 (PST) Received: by mail-ua1-f44.google.com with SMTP id d22so6932947uaw.2; Tue, 08 Feb 2022 07:23:42 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LZ7CP5kqwUe/zKlKUAI4I0ax7qbE+g2pzH6adwlgoSo=; b=1zESSamYy0VUnQrYoCCM1iwZHdpnERjYq2AjbYcTrWzgiPcyO03lA4buDiIEagmpKo Ipp7dWimZdScsyt+N/0pQ8ejX/K/CCuimVYUIKSmXK2J3v/6mtjJ8ZcQ+Qv7zNcHUHGV N1wzr0smHb8v260QUASqVWEuxI70hgBrqNaR3M+/G4qe/yWqGxj26NBbNF1pD1ivSWuI xMhYo+zSBsxighLLEMGwexo49v/RlHe2hNMhL6mCGyd+EF5re3m/njmtqt2IJ2s62C58 YEC/sYKDXWkchagcJAoW0/uqVeuTeH0Jf12KC2RrGOOJGCF7G3wpqXeaAZ85tve8Zl2x FkYA== X-Gm-Message-State: AOAM531tBlOmLwG3yi0BgqJWkliraWvYvImhHZIEdodc8hy/VbLMvoYr 2xxFi47B0Ez5PNofWHrF4n1dD6AjQPO03g== X-Google-Smtp-Source: ABdhPJyzfZmyaqtO/I3rmFIPPUzNcb1vWNVlL0NEKCwiPeB9S96CWQC8OAqvt18JN2w0nnhxUaZrEA== X-Received: by 2002:ab0:36b3:: with SMTP id v19mr1666390uat.101.1644333821629; Tue, 08 Feb 2022 07:23:41 -0800 (PST) Received: from mail-vs1-f43.google.com (mail-vs1-f43.google.com. [209.85.217.43]) by smtp.gmail.com with ESMTPSA id h22sm2970642vsj.0.2022.02.08.07.23.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Feb 2022 07:23:41 -0800 (PST) Received: by mail-vs1-f43.google.com with SMTP id m24so3755191vsp.7; Tue, 08 Feb 2022 07:23:41 -0800 (PST) X-Received: by 2002:a05:6102:34d9:: with SMTP id a25mr334951vst.68.1644333820869; Tue, 08 Feb 2022 07:23:40 -0800 (PST) MIME-Version: 1.0 References: <20220204134347.1187749-1-javierm@redhat.com> In-Reply-To: From: Geert Uytterhoeven Date: Tue, 8 Feb 2022 16:23:29 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays To: Javier Martinez Canillas Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Fbdev development list , Linux PWM List , David Airlie , Daniel Vetter , Mark Brown , Linux Kernel Mailing List , DRI Development , Liam Girdwood , Rob Herring , =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= , Thierry Reding , Maxime Ripard , Thomas Zimmermann , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Lee Jones , Andy Shevchenko , Sam Ravnborg Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Javier, On Tue, Feb 8, 2022 at 4:10 PM Javier Martinez Canillas wrote: > On 2/8/22 15:19, Geert Uytterhoeven wrote: > > On Fri, Feb 4, 2022 at 2:43 PM Javier Martinez Canillas > > wrote: > >> This patch series adds a DRM driver for the Solomon OLED SSD1305, SSD1306, > >> SSD1307 and SSD1309 displays. It is a port of the ssd1307fb fbdev driver. > > > > I gave it a try on an Adafruit FeatherWing 128x32 OLED, connected to an > > OrangeCrab ECP5 FPGA board running a 64 MHz VexRiscv RISC-V softcore. > > > > Findings: > > - Kernel size increased by 349 KiB, > > - The "Memory:" line reports 412 KiB less memory, > > - On top of that, "free" shows ca. 92 KiB more memory in use after > > bootup. > > - The logo (I have a custom monochrome logo enabled) is no longer shown. > > I was able to display your tux monochrome with ./fbtest -f /dev/fb1 test004 I meant the kernel's logo (FB_LOGO_*),. Obviously you need to enable a smaller one, as the default 80x80 logo is too large, and thus can't be drawn on your 128x64 or my 128x32 display. > > - The screen is empty, with a (very very slow) flashing cursor in the > > middle of the screen, with a bogus long line next to it, which I can > > see being redrawn. > > - Writing text (e.g. hello) to /dev/tty0, I first see the text, > > followed by an enlargement of some of the characters. > > So far I was mostly testing using your fbtest repo tests and all of them > (modulo test009 that says "Screen size too small for this test"). > > But I've tried now using as a VT and I see the same visual artifacts. I > wonder what's the difference between fbcon and the way your tests use > the fbdev API. Fbcon does small writes to the shadow frame buffer, while fbtest writes to the mmap()ed /dev/fbX, causing a full page to be updated. 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