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 701B2C352A1 for ; Tue, 6 Dec 2022 13:01:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234956AbiLFNBs (ORCPT ); Tue, 6 Dec 2022 08:01:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235035AbiLFNBR (ORCPT ); Tue, 6 Dec 2022 08:01:17 -0500 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E0AFD130 for ; Tue, 6 Dec 2022 05:00:54 -0800 (PST) Received: by mail-ej1-x636.google.com with SMTP id x22so5932856ejs.11 for ; Tue, 06 Dec 2022 05:00:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=wPt4+hNHEAygAYm/iIi7WWfY6gI8L5cWMRSUMDDponY=; b=bQCKAqQfljf1U+dmf1KTvgvajxOVvy8g4xkI4rqmjigYqgb9X1FMbQ8tIMdrKaz3P6 rctDhvLQTL+2Q4qbe1stTd1+SPdOxXAgcDeFRdvGHLkC4LInwOCbzeVlXod0yH3gpiAr vrxak2zCWhjeVMx+yMy6Vdn5liiPfn/oxVrUaD/UkMpxYVrD+P6N7Bmf4smucUSd/rNo 2Xehk9hDqq8zPpddbXzqRxYnWw1k/32h5/s3p9KEseBLmRGtDxdiNdZEEVps0v+qdwl4 2j+wS2CBuRpXP4IWlQlBxw8lvGERcYYR6izUxZUShkdjLvgzgqcywwDgvqBhKLq7F29H Holg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=wPt4+hNHEAygAYm/iIi7WWfY6gI8L5cWMRSUMDDponY=; b=jFPaJySlamsEy9JT4K/6tcoaS+3IyK73n/GKx2P+/AbJUBCL9oo2E0i3Z4bbuasIdE tcsX9pdpKb6YAYWqcSu+yE9OjWnAyfmzty4afls/okf5VwoEYYlPQ/6Ad2nQp2S1rbol 1jxatIZ8wa2I5Pe2DsUl6w5m1IckzCCsgaFEZVerUNQilRVf9P5JAh890QCelY1tmIDK /uOSVVJbXQrzGm0Nzz8GRSQprNH+qsoUZFuSL8fU1s14USLwfyJKbsnimIQv2IiunVSL Xn1VN9Qm58V+Qh3vVMXEeo7h0SSY/lY4Uyqxa3xzSVx8Iw+GTHx4+x7+PK4FfhpXJcKy 96Dw== X-Gm-Message-State: ANoB5pn9MCzldIdjS2m7PLt1F9ee7CftuLXza4YOGikY7468350CZ1uw 24X3pmJX74Kjjf7tnvdKZ/o/PQ== X-Google-Smtp-Source: AA0mqf4ZqirxuOZeT0doTihcv0ObkbVOPHk5CHTRLxdM1jLRtMbB2+TyECyb6JOuMmm8aMSm/aDMXQ== X-Received: by 2002:a17:906:1585:b0:7ad:84c7:502d with SMTP id k5-20020a170906158500b007ad84c7502dmr58639319ejd.177.1670331652808; Tue, 06 Dec 2022 05:00:52 -0800 (PST) Received: from ?IPV6:2a0e:41a:894f:0:5e13:2125:2912:2c56? ([2a0e:41a:894f:0:5e13:2125:2912:2c56]) by smtp.gmail.com with ESMTPSA id fe17-20020a1709072a5100b0077a8fa8ba55sm7325471ejc.210.2022.12.06.05.00.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 06 Dec 2022 05:00:52 -0800 (PST) Message-ID: <9ec0204d-ca4c-afd9-33d6-1ebaaaf6b144@baylibre.com> Date: Tue, 6 Dec 2022 14:00:51 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [PATCH v3 3/3] drm/tiny: ili9486: remove conflicting framebuffers Content-Language: en-US To: Thomas Zimmermann , neil.armstrong@linaro.org, Daniel Vetter , Jerome Brunet , David Airlie , Kamlesh Gurudasani , Mark Brown , Martin Blumenstingl , Kevin Hilman Cc: linux-amlogic@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20221116-s905x_spi_ili9486-v3-0-59c6b58cbfe3@baylibre.com> <20221116-s905x_spi_ili9486-v3-3-59c6b58cbfe3@baylibre.com> <14e5c4e4-30dd-8efd-81e4-d680664ab04a@linaro.org> From: Carlo Caione In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12/2022 10:52, Thomas Zimmermann wrote: >> Conflicting framebuffer on the SPI display ? How is that possible ? > > Calling drm_aperture_remove_framebuffers() is only required if the > graphics card may have been pre-initialized by the system, such as a > VGA-compatible card on a PC. > > Could the SPI display have been initialized by the firmware? If not, the > call should be left out. What's happening on this board is that the builtin simpledrm driver is creating fb0 backed by the framebuffer prepared by u-boot / grub, and this the framebuffer being used by fbcon at early boot. When the ILI9486 DRM driver is probed later during boot a second framebuffer is created (fb1) and when fb0 is destroyed, fbcon still remains attached to a non-existent framebuffer, so the user is left in the dark. What this patch is doing is that when the ILI driver is probed, fb0 is destroyed and a new DRM-backed fb0 is created by the ILI DRM driver that can be used by fbcon, so the user can correctly see the console on the SPI display. Cheers, -- Carlo Caione