From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 7433D3D9DCD for ; Tue, 29 Sep 2026 10:16:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790677027; cv=none; b=tcV9XCIQPVX26HpTL/Ro87vgSU7jV5GvIIX+gc1V+caBGhom8Jj3iqWkDO47bM5lax/229/5sGLVWvn0KvRT0nwi2/HuX2aaxkGhwuwpyf6BF3TfZVT6ZsVBOpMf6sj34/ny2Star64toytns7Y9bevu+zAwDn7ISRyZppFMgaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790677027; c=relaxed/simple; bh=e//TCcit/ISzMYO0YeFaG6Hi1WgM+P6dvupJ+mrGO14=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=fxlBQ9cxPT9bzAQF5DMv+yjXsRXawieHMFtiDA0ZUB2iXsy2tjzKWgeT39lFJ/xXx7PUSRGlHSV03Fn2GbzO/wzruxZHZi0IrCyhxt8LMY8iaX+sjHMyuGSyJNNDcyekGjOUFWANzTBfXiLZ2OQSDTRVvOlGEIycR2CRAGBgmP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=AjDRPl9X; arc=none smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="AjDRPl9X" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1790677017; x=1822213017; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=e//TCcit/ISzMYO0YeFaG6Hi1WgM+P6dvupJ+mrGO14=; b=AjDRPl9XBa9mA7gFH25PhKH8XRg29+yFQ/RSaqSDS+e1S2xZZilRmN27 p+wx/S8yl6skzrgtPmnxa0Yg070HIbB6JRYqukpA2uUvE3xRLdZ2kA7nY KC0rz5c/DcvjTdBYxxBcUVGnMUbbVy6Qap+Tlpna3TV9X+VeV6stojG99 3BAsNZ9DkybfyWxtSUjGjM4ZmCNkXJqet8zLeNMik4BJ5F2SeEsy+tQjp yQTYKyOZiSQE0xBxbG3zyPobDZZKXfjKmebyGCN+Y2Ihv8gcwi1yIEcru ghYL9wEyo2V1fygtJh0xGXK2EIo0JweGQrDCiRSQZ8vqV5Sw+X1YZ1rFp Q==; X-CSE-ConnectionGUID: 9tBZqgUSTpuy7k921+FzMA== X-CSE-MsgGUID: +qd7kPQRRk6PIn27F/RMeg== X-IronPort-AV: E=McAfee;i="6800,10657,11919"; a="101558569" X-IronPort-AV: E=Sophos;i="6.27,130,1787036400"; d="scan'208";a="101558569" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2026 03:16:53 -0700 X-CSE-ConnectionGUID: mcFPh+TaRTGZ537dHTcCpQ== X-CSE-MsgGUID: xQ/qpcy8QsmvUL+LJw7xhQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,130,1787036400"; d="scan'208";a="271815009" Received: from kniemiec-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.244.233]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2026 03:16:44 -0700 From: Jani Nikula To: Benjamin Tissoires Cc: Maxime Ripard , Neil Armstrong , Jessica Zhang , David Airlie , Simona Vetter , Maarten Lankhorst , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Florian Fainelli , Broadcom internal kernel review list , Andrzej Hajda , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Albert Esteve , Dave Stevenson , Javier Martinez Canillas , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, llvm@lists.linux.dev, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/6] drm/bridge: Add a BPF-based MIPI-DSI panel driver In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20260928-drm-mipi-dsi-panel-ebpf-v1-0-5244926aace4@kernel.org> <054ef52478fc93fc213a9dae23ea77f73094aaf2@intel.com> Date: Tue, 29 Sep 2026 13:16:41 +0300 Message-ID: <42cfa3fb2246c66d69e45d7d9b8d6aaadc0da4c4@intel.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, 29 Sep 2026, Benjamin Tissoires wrote: > Ouch. This immediately raises the "let's implement a parser in the > kernel" flag, or "let's create a new langage". Fair. > You'd still need a dedicated driver for your new blob parser, with far > fewer people who had had a look at it than BPF who has been working on > for several years. Fair. > The integration of BPF and the kernel is honestly transparent nowaday: > calling a struct_ops BPF function is just a function call away, and from > the bpf calling anything in the kernel is also just a call away. I don't know if I'm just being overly conservative here, but it seems to me BPF provides too much flexibility for the use case. But maybe the point is completely moot, and you should just ignore me. ;) > See Maxime's answers: yes, falling back to dedicated driver is still > encouraged. [Moved the above to go with below.] > Isn't that what Maxime wants to have? One driver for a plethora of DSI > panels, with the same ability the BIOS has to also do function calls to > set things up? I suppose this is something that could use some clarification. Is the idea that most (simple) dedicated panel drivers eventually get converted to BPF? Or is the idea that BPF is easy for prototyping and development using stable kernels and short time to market, and most of them would eventually get converted to dedicated panel drivers? The story wrt display before userspace is up and running also needs clarification. BR, Jani. -- Jani Nikula, Intel