From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C96FEC04FDE for ; Mon, 12 Dec 2022 23:37:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233745AbiLLXhK (ORCPT ); Mon, 12 Dec 2022 18:37:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232791AbiLLXhJ (ORCPT ); Mon, 12 Dec 2022 18:37:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21202192A5; Mon, 12 Dec 2022 15:37:09 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D7698B80F93; Mon, 12 Dec 2022 23:37:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C419C433D2; Mon, 12 Dec 2022 23:37:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670888226; bh=Djj37c4gGhHcy/TCgXVD2eUrZ4pas0KvVlsKKNOhTNQ=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=JqE69LucO9qZIWAElN4CUCwwAlIBQJxrkL1lTmaYO/UObCARO+ktTV5RySUi3LCB5 7YsLSUmFNNzZl4JewOsbhOvKiKjM0RHsfIuUPfKAbs+Y0mVLq7NFuK9DKtRvBBqbVg g917KtwjIY2YE0OBF5Udwyf90w+WByk9dUB+vR47v8BuJsrh7ZaUEWK/SHJVeHudyc 0weqMuFrEYAtB9hs/Y0NVpzzfGkDLm6R7QMW09zo1IbcO9ljJkGj2XrSdc5USpUoMs x+dle18vHpIq8mAvzbihUE4xM/Q2P16omsQBYQeQVpTTMKO9McXduXtcCQhbUhU5Gm A8S6LgCd3pEqQ== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <8b42763d-5fc3-3853-c421-227494c0144a@seco.com> References: <20221027191113.403712-1-sean.anderson@seco.com> <20221027191113.403712-5-sean.anderson@seco.com> <20221027230331.19C2FC433D6@smtp.kernel.org> <5f00ede6-10f5-c11c-ee21-54460c1f98b0@seco.com> <20221101201020.B6180C433C1@smtp.kernel.org> <45463950-7a4f-758d-d6a1-b8fdf9bfd319@seco.com> <20221207021742.A3596C433C1@smtp.kernel.org> <8b42763d-5fc3-3853-c421-227494c0144a@seco.com> Subject: Re: [PATCH v8 4/9] phy: fsl: Add Lynx 10G SerDes driver From: Stephen Boyd Cc: Rob Herring , Bagas Sanjaya , devicetree@vger.kernel.org, Krzysztof Kozlowski , linuxppc-dev@lists.ozlabs.org, Ioana Ciornei , linux-arm-kernel@lists.infradead.org, Camelia Alexandra Groza , Madalin Bucur , Jonathan Corbet , Michael Turquette , linux-clk@vger.kernel.org, linux-doc@vger.kernel.org To: Kishon Vijay Abraham I , Sean Anderson , Vinod Koul , linux-phy@lists.infradead.org Date: Mon, 12 Dec 2022 15:37:04 -0800 User-Agent: alot/0.10 Message-Id: <20221212233706.6C419C433D2@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Quoting Sean Anderson (2022-12-08 07:36:45) > On 12/6/22 21:17, Stephen Boyd wrote: > > Quoting Sean Anderson (2022-11-01 16:27:21) > >> On 11/1/22 16:10, Stephen Boyd wrote: > >> >>=20 > >> >> Oh, I remember why I did this. I need the reference clock for clk_h= w_round_rate, > >> >> which is AFAICT the only correct way to implement round_rate. > >> >>=20 > >> >=20 > >> > Is the reference clk the parent of the clk implementing > >> > clk_ops::round_rate()? > >>=20 > >> Yes. We may be able to produce a given output with multiple reference > >> rates. However, the clock API provides no mechanism to say "Don't ask > >> for the parent clock to be rate X, you just tried it and the parent > >> clock can't support it." So instead, we loop over the possible referen= ce > >> rates and pick the first one which the parent says it can round to. > >>=20 > >=20 > > Sorry, I'm lost. Why can't you loop over possible reference rates in > > determine_rate/round_rate clk op here? >=20 > This is what I do currently, but you need to have the parent clock to do > so. With your suggested method, we never actually get a struct clk(_hw) > which we can query for rate support. The clk_hw for the parent is given to the determine_rate clk_op in the clk_rate_request structure. It's stored in the best_parent_hw pointer when the determine_rate function is called. Does that work for you?