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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14D4FC2BA19 for ; Thu, 23 Apr 2020 10:40:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFD9F2098B for ; Thu, 23 Apr 2020 10:40:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587638404; bh=DJrwxV1CteilAyNbnpDxy4pVpFE/V0iDtEse9XqxW7U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=GkjJ+z8iCTF1lCmvOYfMk6gvmuCSaQELfFX8BUAx+rgj2XnYI8huJK/dmJs76t3RX 6wMmmXSLSPwe4aRqvmPPHrN1vIBTD9xWypBZ//bEW3OKjyQS2URWRsMFwBVjTNFY6Z lRCdcLC2hLBwCdGt33NBpLdhGQtjjgVGdOoOFMGQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727117AbgDWKkD (ORCPT ); Thu, 23 Apr 2020 06:40:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:34226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726997AbgDWKkD (ORCPT ); Thu, 23 Apr 2020 06:40:03 -0400 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B4AE20857; Thu, 23 Apr 2020 10:40:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587638403; bh=DJrwxV1CteilAyNbnpDxy4pVpFE/V0iDtEse9XqxW7U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MXH8k7YYtHTeDgrX6stnMRK5CYXgWnbUvKzpNRvYRFS7xVxtsqPfoCLIEjlMYjnIp 1/8e22g2lQPTzQ1J2bODauQku9OLnacH9tEFbiZb092AV338itzshIzRmTYhQ1kMRI CO+hfULCoccd4Zbi7T7Iu7Z4tQnOi2scRUjgVcsY= Date: Thu, 23 Apr 2020 11:40:00 +0100 From: Mark Brown To: peng.fan@nxp.com Cc: rafael@kernel.org, linux-kernel@vger.kernel.org, linux-imx@nxp.com, shengjiu.wang@nxp.com Subject: Re: [PATCH] regmap: mmio: prepare/unprepare clk only when read/write Message-ID: <20200423104000.GD4808@sirena.org.uk> References: <1587620791-5279-1-git-send-email-peng.fan@nxp.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="AkbCVLjbJ9qUtAXD" Content-Disposition: inline In-Reply-To: <1587620791-5279-1-git-send-email-peng.fan@nxp.com> X-Cookie: This unit... must... survive. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --AkbCVLjbJ9qUtAXD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 23, 2020 at 01:46:31PM +0800, peng.fan@nxp.com wrote: > From: Peng Fan >=20 > use clk_prepare at the very beginning will invoke pm runtime resume, > if the clk is binded with a power domain. This will cause runtime > power high. Let's use clk_prepare_enable and clk_disable_unprepare > when read/write to avoid the runtime power issue. This will mean that we're doing clk_prepare() during I/O which isn't good since for MMIO regmaps we support I/O operations in atomic contexts. --AkbCVLjbJ9qUtAXD Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl6hcH8ACgkQJNaLcl1U h9C17Qf/fo2ZNApBE+9ZJmGgA/okKIKMIRmlk4OQFFeJsttGsP7t5k28YoZr5OAp lRXBkQIeYbA2SmqQmAm0MCowjHv+bX+dUCoZvPr8ghk0j5zSAPfdCe1pXyEBASQl bpBuqx2qr5e75sCnxZ57URuJnSPyHtWF0RYlSW+uTt3OJ9Zz2PNHaWA4Bg6WXxgj qGqEsjpsplrI5Qt88+/nF32NgBENkHUI4glAthZQDirrjzu7dH3z6L+LDwtUTWeG nd9mY3Z6atKt6B4EjRtIlny9JEvETiLpHepdAWJ8oprkHWuDtYRO27n89DyEJVch EJT65ClClqHV9p/sUNO2Uu0QIUtpPg== =DT/v -----END PGP SIGNATURE----- --AkbCVLjbJ9qUtAXD--