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 E5785C433EF for ; Tue, 1 Feb 2022 14:36:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239386AbiBAOgL (ORCPT ); Tue, 1 Feb 2022 09:36:11 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:38724 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239320AbiBAOgJ (ORCPT ); Tue, 1 Feb 2022 09:36:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643726169; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c1qqBdKQoPCwA2ePd7jBkicuBscZF3IvkLQTjtTxA/c=; b=a7eUnWPrmga2Ef1jvyEh5tApsmsNQau8UJgN5MSkVmy1zwkTBbrBQVQvPWbL8xdY75qW1O VdJha6Ou0d7DIpw6JJMp/Ug627tJJPqxDM8e1gach61p//QccvK3JMTVXkLzbUg49pbvCR 7EgVn5nb2LNVH87+dhEMaNwYn++iaIg= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-463-MVfuuQoRPzaP8B0Aqrfy6w-1; Tue, 01 Feb 2022 09:36:08 -0500 X-MC-Unique: MVfuuQoRPzaP8B0Aqrfy6w-1 Received: by mail-wm1-f71.google.com with SMTP id w5-20020a1cf605000000b00354d2d83490so106907wmc.4 for ; Tue, 01 Feb 2022 06:36:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=c1qqBdKQoPCwA2ePd7jBkicuBscZF3IvkLQTjtTxA/c=; b=sLzIqMUC3JhQ3ZhbuuB4c3FXQTUAg4KYpDTk5uUhlu3g+vNwLS0M1hXq/FDupCWRcU NfcEh21OALuJQw6kfmrevZd4mfhJsEF+Qj93RYGiZVfc/ejre3cqEIlmadnXC6oHcsFx vEluaXKedUDi9wNxIzFswOihrSgpdnj9lrsYlfnk22EqE9u8xwXYRSIa16pzchj+JjeY r4BkVXhCkk2i2HQufKrCWDZor7mIvFstJVSSuUBborPPPLNgJRroJC1qCX0+JeInNoni 0hEyzZHwvfKYvVplotViEJATaIv1T0tRdgNJbCg/rFPkB9Jn7HeKTv2dJbr6ZXKbqe3G b70g== X-Gm-Message-State: AOAM532QDYOew/xcb9cg3zbkbN5uT+6jYYV7/zw8z3or2zPR2yVk6E/N lLU5I1wGCzGWnE1247LaSRz24i6WDSJ2WgK+Kagk5strruMQjMRFOhM5TSM+pCTOguGDmWBC76O vwk5YvfkVNv09REtRpYIZiKcn X-Received: by 2002:a7b:c003:: with SMTP id c3mr2022318wmb.80.1643726166848; Tue, 01 Feb 2022 06:36:06 -0800 (PST) X-Google-Smtp-Source: ABdhPJyWEsVQ1UNLWnla5O+uQQySFc68PN6z96VL15rWk5+1TFXROa0fVwYLO5ACOVmJk7fJj5i8fA== X-Received: by 2002:a7b:c003:: with SMTP id c3mr2022299wmb.80.1643726166675; Tue, 01 Feb 2022 06:36:06 -0800 (PST) Received: from [192.168.1.102] ([92.176.231.205]) by smtp.gmail.com with ESMTPSA id h18sm17864523wro.9.2022.02.01.06.36.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 01 Feb 2022 06:36:06 -0800 (PST) Message-ID: <3df2add7-6034-0527-825a-74e62e76dace@redhat.com> Date: Tue, 1 Feb 2022 15:36:04 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 3/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Content-Language: en-US To: Geert Uytterhoeven Cc: Thomas Zimmermann , Linux Kernel Mailing List , Linux Fbdev development list , Daniel Vetter , DRI Development , =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= , Maxime Ripard , Andy Shevchenko References: <20220131202916.2374502-1-javierm@redhat.com> <73dbc5c7-b9e2-a260-49a6-0b96f342391e@redhat.com> From: Javier Martinez Canillas In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/1/22 15:05, Geert Uytterhoeven wrote: > Hi Javier, > > On Tue, Feb 1, 2022 at 2:02 PM Javier Martinez Canillas > wrote: >> On 2/1/22 10:33, Thomas Zimmermann wrote: >>>> +{ >>>> + u8 col_end = col_start + cols - 1; >>>> + int ret; >>>> + >>>> + if (col_start == ssd1307->col_start && col_end == ssd1307->col_end) >>>> + return 0; >>>> + >>>> + ret = ssd1307_write_cmd(ssd1307->client, SSD1307_SET_COL_RANGE); >>>> + if (ret < 0) >>>> + return ret; >>>> + >>>> + ret = ssd1307_write_cmd(ssd1307->client, col_start); >>>> + if (ret < 0) >>>> + return ret; >>>> + >>>> + ret = ssd1307_write_cmd(ssd1307->client, col_end); >>>> + if (ret < 0) >>>> + return ret; >>> >>> Can you write these cmds in one step, such as setting up an array and >>> sending it with ssd1307_write_array? >> >> I don't think so because the commands are different. But I'll check the >> ssd1306 datasheet again to confirma that's the case. > > IIRC, I tried that while working on the optimizations for ssd1307fb, > and it didn't work. > That's what I would had expected by reading the datasheet. Thanks a lot for confirming my assumption. Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat