From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 726183537D0; Sat, 30 May 2026 08:54:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780131262; cv=none; b=PqGbprBEXcdKaJiMjSNatAL1T8D5lTS4cC35hFEvEalWK3HhWhXCnq10Z1829t65Yb6maXYbWjL+fwVqx5PQr7skqwr9mYhu2/x6J7POFE0u0fsD6b5xbmmjPALos+8APRL0ZCbq3laIFm22Sld1Aanf5asUbWEkhlpOpT7ewHE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780131262; c=relaxed/simple; bh=ALak2iGU2vL9VpRA29lMsenoQwE/u2+TIXdrQy9k3n0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=r+GZw58h57627bBsa97Wrrn9dNuoLwVHT7/0WEAYjWcjYt4hxTyjTyqhOIAVLvUwrBJ3rWuqy/ckwoAm22kf/zf1Xh3PExwPaAh7vtP9iZmv3V0/z6yw8W1AyyxJ4a5O2XM5NaRf5WJeauZzNM64cOs/ZQonrnqG7einf/biDHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q6KFv3Bw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Q6KFv3Bw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85E0F1F00893; Sat, 30 May 2026 08:54:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780131261; bh=CXpgVm9FxGfdae5u6tycGwxDHBkrtPMkQwMJjdDB8gk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Q6KFv3BwM6JMSJwQcqUKvrjKu16gTjCSqGmn8Qi0ILzyQf/8U9XQjtMYl0508qdue QmfEkX4COYHW7zpK5La9eWyDvhsrNq3CENfkWN1yW66RtARad4S9aqbmtqdvb3T96+ JEzDEdqa0HjN+lVq7X9Cp5BRSELn1yw7i8SubKlFaKRzp6yjBoDterDYEcbyKd7vBY 6DKcWdq8llzS018We8Ozoib3T7eT2BIu8+45dNRztwlKpSLhfFQYPQ0m6nx4LN0oDL 8RoBMKr5Tb8sGF87O1mKAVhHkVLjJH1M3Rodvkc3Z0MQKABwc9Y9aAjLkRQmXH3QI5 1ssobfUStmUIA== Date: Sat, 30 May 2026 10:54:18 +0200 From: Krzysztof Kozlowski To: Conor Dooley Cc: Santhosh Kumar K , broonie@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, miquel.raynal@bootlin.com, 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 Message-ID: <20260530-precise-practical-jaguarundi-81faa6@quoll> References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-2-s-k6@ti.com> <20260528-clergyman-kindling-20971775ba78@spud> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260528-clergyman-kindling-20971775ba78@spud> On Thu, May 28, 2026 at 06:36:57PM +0100, Conor Dooley wrote: > On Wed, May 27, 2026 at 11:25:15PM +0530, Santhosh Kumar K wrote: > > Some SPI controllers support high-speed operating modes that require > > controller-side configuration before the device can be driven at its > > rated maximum frequency. In these cases two frequencies are relevant: > > a conservative speed usable without any such configuration, and the > > maximum speed achievable once the controller is set up accordingly. > > > > The existing spi-max-frequency property accepts only a single u32, > > which cannot express this distinction. Extend it to accept either a > > single value (retaining full backward compatibility) or a two-element > > array [base-frequency, max-frequency], where base-frequency is the > > conservative operating speed and max-frequency is the highest speed > > the device supports after controller-side configuration. > > > > Signed-off-by: Santhosh Kumar K > > --- > > .../devicetree/bindings/spi/spi-peripheral-props.yaml | 10 ++++++++-- > > 1 file changed, 8 insertions(+), 2 deletions(-) > > Pretty sure this hasn't been tested, dt_binding_check cannot even build > processed-schema.json with this applied because there are multiple > definitions of spi-max-frequency with it applied. > > The sashiko makes the point that this breaks every binding that uses > minimum/maximum to set constraints too, because these properties do not > apply to arrays unless applied per item. > > I also don't get the point of this property, why can't you just set the > max that the device can do and if the controller can configure itself to > be fast enough it will do so, and if it can't then it'll pick whatever > the fastest it can actually do instead? > Seems like you're abusing a peripheral property to encode information > about the controller. Yes, commit msg speaks about controller but patch body changes SPI devices. Best regards, Krzysztof