From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.35 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793967568; b=DcF0HcCy/knJrjQeM+OBydtEUCElQnmj5c0khKC5JaUD403aAUtHpf51LjEjIqy3v1xt TjKjjI2wZFXgHyeld2e/X/gPEwWpkJBRk1/VFaCxLDx4XhNA5Ene5+ogwXiIVVwIXMW5m K/rvmEZy6aq1spOhc+f4t+tM5WDJTkCYiRqZYdirAWVzgnnHUeOXVVUCHDRWB8RI5zQJw fJxhYadtSqHMlXkqYGv+uQE5da2jhEiIcbwkv5HoUDUkWbRZ5zZBget6AAHMBRDV4aX6k x8HKNFWywe2N4zDiULPHlpxd4mfg7Kb76t8JcWSqd161OFqDGpkxFKPDc8mm7v95RHg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793967568; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=0vUodaVAX93mqin2v1QRnZrq0sGDMtFLDBopNWg3Nj0=; b=x08w0xyadTLZG5aek4LNhMwl7DMkNqtW82ci7fu2P2d0/HwnmPuhQcFNIC1a0dnpZ4FN etf0h5wL9DOeWvYXa/i+40BFPfRnhUruBplsHGPDUM1cSHKtaCkgtVH979iU/urF4uar3 QKfRMU8bR3oufa1S4OgtHNusDOkQgSKHNoE1PdTTW6ZLGml3bU04V0z9sVp4CU3dHO0a+ hS1temHDRr622p0gGaNukshU+mjwnEkU0LlQXPhgH4BtoO0MC+STvewtis9xehHCg8sGw MMDXEPqNZFDpXCEoxXOV1xncaVgqFHIzjZtU4kayFJnhepIyA15wCrnQPrqimIGQX8w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=V5G0adXI; arc=none smtp.remote-ip=91.218.175.35 Received: from mta0.migadu.com (out-35.mta0.migadu.com [91.218.175.35]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66FE1606A326 for ; Fri, 6 Nov 2026 12:19:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 66FE1606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=V5G0adXI X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=UjpdCFHkVQinke0+LhWk+0IZR4eqn7V48c0aBGCBqmM=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793967564; v=1; x=1794572364; b=V5G0adXIb2lsE3Gshq9LuKJbAg5bI+F8TdF831riiz2dwOtFOnthMGJ1DD8ovycfnsqfJCX/ 6U7vCM1JJanEDINxX/xUDk2m1fAsLhqHwJuJSD33bPrkoHvu60W8QGwOWmmq6Bi2/LCzhz0tcjZ Qvt35+skZqDdWbc9VKphXNY0= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f0b4435a6e72b80c; Fri, 06 Nov 2026 12:19:24 +0000 X-Mizu-Trace-ID: f0b4435a6e72b80c X-Migadu-Flow: FLOW_OUT Message-ID: Date: Fri, 6 Nov 2026 13:19:23 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] ASoC: SDCA: Add port constraints into sdca_asoc_set_constraints() To: Charles Keepax Cc: broonie@kernel.org, lgirdwood@gmail.com, yung-chuan.liao@linux.intel.com, linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org, patches@opensource.cirrus.com References: <20261105134952.1728147-1-ckeepax@opensource.cirrus.com> <20261105134952.1728147-3-ckeepax@opensource.cirrus.com> <1cae1b17-4c49-4a10-922e-c552e90593c4@linux.dev> Content-Language: en-US From: Pierre-Louis Bossart In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit >>> - if (entity->type != SDCA_ENTITY_TYPE_IT) >>> - return 0; >>> + /* FIXME: Currently only a single unshared port is supported */ >> >> I must admit I have no idea how we'd handle ports that can be connected >> to multiple terminals. It's allowed in the spec, even between Functions >> which are then no longer independent, and I was told it was due to >> hardware restrictions, but still I hope we never have to deal with this... > > lol yeah me too. For now I am mostly just putting these FIXME's > in at all the places where this is going to become relevant. I > must confess I haven't reviewed this part of the spec in detail. > It feels like sharing a couple of ports for a single terminal is > probably tractable if a little annoying. But yeah, if we got as > far as sharing a port across functions that seems like a total > nightmare. We would probably need to do a bit of re-architecting > and add a port abstraction at the device level, but hopefully > people are wise enough to not build hardware like that. I re-read the spec and I think the main usage for the Terminal to ports mapping is bandwidth management, possibly across multiple lanes. But that's a 1:N terminal to port mapping, not M:1 or M:N. It's complicated but not earth-shattering. Also the mapping is supposed to be pre-made in DisCo tables, not something that requires much intelligence in drivers - until the tables are wrong but that's a different story. I didn't see any wording on sharing ports across functions, I am 100% sure this was talked about in the WG but maybe it didn't make it in the final 1.0 version. That said it's not described as forbidden either so a well-intended creative hardware designer will probably make that "optimization" at some point...