From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 003C62D5C8B for ; Tue, 2 Sep 2025 16:04:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756829095; cv=none; b=UUnbPumJAaGh5wmeTGSXjYPCfOby2WVjaTJSbF5+721KozmYc7wkzkSeTlk8TObKZy5LEJz01EEWHDN+7SFHGl47YFWtklxnNBUxDNoFWRTWXw4vS0Y8xjcvW7lrlcPnx/jvVNnzOB6MP7nXZrL7lrIFMX8RzYqqhOLBN58767s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756829095; c=relaxed/simple; bh=ovWdbmcLBmA33JBDYg84OE2PqHzIKb6iNt+T6eoF2kw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QB7AxXn0eBsyGeoMT5EqqFd5C1eUf9ba7bV1zKYG/oX9RKGszIuLW0T75CMbpHbRRgbkv6tEHbs070Vnm25JQpf8ceuJ7/Ykct2gHwDQEmjauaH9gHCe4v+xgnluWTXSxiKOvZit0Wh05LnAEolSszFEYPw2VwBYS5oxNpvXNfw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=FUUfI3WX; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="FUUfI3WX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1756829092; bh=ovWdbmcLBmA33JBDYg84OE2PqHzIKb6iNt+T6eoF2kw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FUUfI3WXYc1B8QJ6WeBpPvR0+1cMVN778Sl29SAmhAoSko8l+RH/Bxm0WuqqyJJW1 lrMAWYbfZ80CGBKTAcbSG/5phmbYDtRElhkRWQsS9uubdqJ8wRB8MMfG+ZuqR0EuH5 cc4hQYsR8yFJX4o5sAEOP2F17NHZFKm/Loaa7WpvuUrKY1fNLRA9RgbCkxZUyWSGld ZMvRimQ+t3ZM3ANHSvPz18MV+Wjp08FasY9xoJR+TY+A4eE9FUKLI9OF72e5kPK8jO J7wJyFTpc76oxwxhQbs+xMKsWOMZ1oUXQNvGMP9PG9O5KdeNyGwlOdVxEehCPDsBh3 4dG8NXOEAcTIg== Received: from [192.168.1.90] (unknown [82.79.138.60]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id 5E63E17E131D; Tue, 2 Sep 2025 18:04:51 +0200 (CEST) Message-ID: Date: Tue, 2 Sep 2025 19:04:50 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] Introduce BACKGROUND_COLOR DRM CRTC property To: Raphael Gallais-Pou , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sandy Huang , =?UTF-8?Q?Heiko_St=C3=BCbner?= , Andy Yan Cc: kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, Matt Roper References: <20250902-rk3588-bgcolor-v1-0-fd97df91d89f@collabora.com> <50e3f25c-f4e1-40f6-8e36-23193863f1ee@foss.st.com> Content-Language: en-US From: Cristian Ciocaltea In-Reply-To: <50e3f25c-f4e1-40f6-8e36-23193863f1ee@foss.st.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Raphael, On 9/2/25 4:19 PM, Raphael Gallais-Pou wrote: > > > On 9/2/25 11:27, Cristian Ciocaltea wrote: >> Some display controllers can be hardware-configured to present non-black >> colors for pixels which are not covered by any plane (or are exposed >> through transparent regions of higher planes). >> >> The first patch of the series introduces the BACKGROUND_COLOR DRM >> property that can be attached to a CRTC via a dedicated helper function. >> A 64-bit ARGB color value format is also defined and can be manipulated >> with the help of a few utility macros. > > Hi Cristian, > > Thanks for this work ! :) > > FWIW I sent a series also based on Matt's work four years ago: > https://lore.kernel.org/dri-devel/20210707084557.22443-2-raphael.gallais-pou@foss.st.com/ > > IIRC at the time there was some questions around the pixel format used for the > property, and non-opaque color vs alpha pre-multiplication. > Mind that on STM32MP platforms alpha channel for the background color is not > supported. > > Hope the thread can bring some insights. Thanks for pointing this out, I will consider it for v2. Regards, Cristian