From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 4D0F31A6822; Thu, 4 Jun 2026 07:14:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780557266; cv=none; b=SVCBzdZhiXGruUgsf9OgDUwlwdXJlk0d1p2kymEWmBK59cDxqU8Cu5kAL3ubBeUYBiAdXKZEUvzfCrhljoekltMVgIlHgH8/1gB+O5RpDz0dN6P22bcAT+tMbyf4Mjma/hFTRPi/JESTXB1iTz56u+iQqbIwWj5FF/YbMkAWEyU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780557266; c=relaxed/simple; bh=Mch2Bg7cryJTjKT8MYD1B/J4muhxyP20EtAZ3/VXcdA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=cNKJIFrF0TuYWgIEC55fMxHFTErW59Mb1pft9wagmqSNjCB9+tVxG5YjmrLKNyLbM4JHKPaGAtDWKYxgjKCYoujdf1HkiKLrnK0nhyHhfvMTz8iNgmarrlus5yyFJ1FsRHUiDQoZBiYA0CydrH/cc671T9YhR+ip6towlrtScmg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=g4CCWlRq; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="g4CCWlRq" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id BF5811A0589; Thu, 4 Jun 2026 07:14:22 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 910585FEF7; Thu, 4 Jun 2026 07:14:22 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id B3CD8106A173C; Thu, 4 Jun 2026 09:14:17 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1780557261; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=Mch2Bg7cryJTjKT8MYD1B/J4muhxyP20EtAZ3/VXcdA=; b=g4CCWlRqCPHFmctTPJZrGv/lHwBZoYZJfY82Uov46VdGISP3Ol0WtQjBizs0npkiHcVgiR fmaD1FHs3F3fgInEirfZ9SwbUKPH2NlYQf2qbp23yLfBCWNKkwAJKtGQ+YDKXG43ieaxXi vQ75VE/PCZJEOabzNNUNORO/TmFcjLyM65wDaiut99qScvAGyQtvTb/bY7dJKqFiNVG/EC 0MRiTAeKvoRTFfnDVUvWfRkOf1T4lxAcGWsIHAYiUKT72LhjeLbJf3O6S3WWBXBJ6kGsP8 JpdpqnK0JGcpG1S0TKz7GB3a24RK+eiWPkEqe7HJkbRoa2jkqleMe1rbD4xwPg== From: Miquel Raynal To: Conor Dooley Cc: Santhosh Kumar K , broonie@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, richard@nod.at, vigneshr@ti.com, pratyush@kernel.org, mwalle@kernel.org, takahiro.kuwano@infineon.com, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, praneeth@ti.com, u-kumar1@ti.com, a-dutta@ti.com Subject: Re: [PATCH v3 01/13] spi: dt-bindings: allow spi-max-frequency to specify a frequency pair In-Reply-To: <20260603-balance-encounter-94f69e1577f3@spud> (Conor Dooley's message of "Wed, 3 Jun 2026 17:40:15 +0100") References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-2-s-k6@ti.com> <20260528-clergyman-kindling-20971775ba78@spud> <87cxy92llq.fsf@bootlin.com> <20260602-aptly-bunkbed-1bd3a8d63d54@spud> <875x3zzkji.fsf@bootlin.com> <20260603-neatly-twine-e89b923f5cb6@spud> <87o6hry4d4.fsf@bootlin.com> <20260603-balance-encounter-94f69e1577f3@spud> User-Agent: mu4e 1.12.7; emacs 30.2 Date: Thu, 04 Jun 2026 09:14:16 +0200 Message-ID: <87ik7yydyv.fsf@bootlin.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Last-TLS-Session-Version: TLSv1.3 Hi Conor, >> >> > Right, and this I guess is what scuppers letting the controller dri= ver >> >> > sort the configuration out itself and leaving the property as-is. >> >> > It could be that the speed in spi-max-frequency is lower than the "= base >> >> > speed" of the controller but because of board routing or device >> >> > capability that the tuned mode is still required, right? >> >>=20 >> >> I do not actually expect any tuned mode/frequency to be mandatory. >> > >> > I think you misunderstood my use of "required", I meant that the new >> > property/information was needed in the scenario I described, not that = it >> > should be a required property in a binding. >>=20 >> Yes I misunderstood the term indeed. However I still fail to catch what >> you meant here, I'm sorry. Would you mind rephrasing? > > I was talking about a scenario where you want to use the tuned mode to > achieve the maximum rate because of the device and/or board configuration, > but the rate is below the point where the controller would need tuning. > Say the controller needs tuning above 8 Hz but the conditions require > tuning to achieve more than 5 Hz. In this example, if the device can do > 6 Hz, spi-max-frequency (in the current form) would be set to 6 Hz, and > the controller would not enable the tuned mode, leading to problems > because the inflection point determined from the controller compatible > of 8 Hz would not have been reached. I don't think this is a real situation. If the "conditions", as you say (ie. PCB routing, mostly) require tuning above 5, then spi-max-frequency should be 5. It is the frequency that is reachable without any tuning. Tuning is just a plus. If tuning fails, we fallback to the regular "base" speed, which just works. Thanks, Miqu=C3=A8l