Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753356AbeADPSb (ORCPT + 1 other); Thu, 4 Jan 2018 10:18:31 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:33711 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753238AbeADPS3 (ORCPT ); Thu, 4 Jan 2018 10:18:29 -0500 Subject: Re: [PATCH v6 3/6] can: m_can: Add PM Runtime To: Faiz Abbas , wg@grandegger.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, nsekhar@ti.com, fcooper@ti.com, robh@kernel.org, Wenyou.Yang@microchip.com, sergei.shtylyov@cogentembedded.com References: <1513949488-13026-1-git-send-email-faiz_abbas@ti.com> <1513949488-13026-4-git-send-email-faiz_abbas@ti.com> <1308ee81-a1e9-ac5a-2d97-334fa825ef8d@ti.com> <7d857263-14a7-6001-8f13-42d80f757573@pengutronix.de> <6bdaab16-cb16-e039-473c-52dd295bd4ba@ti.com> From: Marc Kleine-Budde Message-ID: <31b6a902-19d9-2068-1028-b95dfba036bb@pengutronix.de> Date: Thu, 4 Jan 2018 16:18:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <6bdaab16-cb16-e039-473c-52dd295bd4ba@ti.com> Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="mILBW1zXMwVlUrZ8tOETLXDbr33dozHgF" X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --mILBW1zXMwVlUrZ8tOETLXDbr33dozHgF Content-Type: multipart/mixed; boundary="KIt3gJ0iOZIS8x9PKgdXdKuDa71mnuNQl"; protected-headers="v1" From: Marc Kleine-Budde To: Faiz Abbas , wg@grandegger.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, nsekhar@ti.com, fcooper@ti.com, robh@kernel.org, Wenyou.Yang@microchip.com, sergei.shtylyov@cogentembedded.com Message-ID: <31b6a902-19d9-2068-1028-b95dfba036bb@pengutronix.de> Subject: Re: [PATCH v6 3/6] can: m_can: Add PM Runtime References: <1513949488-13026-1-git-send-email-faiz_abbas@ti.com> <1513949488-13026-4-git-send-email-faiz_abbas@ti.com> <1308ee81-a1e9-ac5a-2d97-334fa825ef8d@ti.com> <7d857263-14a7-6001-8f13-42d80f757573@pengutronix.de> <6bdaab16-cb16-e039-473c-52dd295bd4ba@ti.com> In-Reply-To: <6bdaab16-cb16-e039-473c-52dd295bd4ba@ti.com> --KIt3gJ0iOZIS8x9PKgdXdKuDa71mnuNQl Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: quoted-printable On 01/04/2018 04:17 PM, Faiz Abbas wrote: > Hi, >=20 > On Wednesday 03 January 2018 08:47 PM, Marc Kleine-Budde wrote: >> On 01/03/2018 04:06 PM, Faiz Abbas wrote: >>> Hi, >>> >>> On Wednesday 03 January 2018 07:55 PM, Marc Kleine-Budde wrote: >>>> On 01/03/2018 01:39 PM, Faiz Abbas wrote: >>>>> On Tuesday 02 January 2018 09:37 PM, Marc Kleine-Budde wrote: >>>>>> On 12/22/2017 02:31 PM, Faiz Abbas wrote: >>>>>>> From: Franklin S Cooper Jr >>>>>>> >>>>>>> Add support for PM Runtime which is the new way to handle managin= g clocks. >>>>>>> However, to avoid breaking SoCs not using PM_RUNTIME leave the ol= d clk >>>>>>> management approach in place. >>>>>> >>>>>> There is no PM_RUNTIME anymore since 464ed18ebdb6 ("PM: Eliminate >>>>>> CONFIG_PM_RUNTIME") >>>>> >>>>> Ok. Will change the commit message. >>>>> >>>>>> >>>>>> Have a look at the discussion: https://patchwork.kernel.org/patch/= 9436507/ : >>>>>> >>>>>>>> Well, I admit it would be nicer if drivers didn't have to worry = about=20 >>>>>>>> whether or not CONFIG_PM was enabled. A slightly cleaner approa= ch=20 >>>>>>>> from the one outlined above would have the probe routine do this= : >>>>>>>> >>>>>>>> my_power_up(dev); >>>>>>>> pm_runtime_set_active(dev); >>>>>>>> pm_runtime_get_noresume(dev); >>>>>>>> pm_runtime_enable(dev); >>>>> >>>>> This discussion seems to be about cases in which CONFIG_PM is not >>>>> enabled. CONFIG_PM is always selected in the case of omap devices. >>>> >>>> Yes, but in the commit message you state that you need to support >>>> systems that don't have PM_RUNTIME enabled. The only mainline SoCs I= see >>>> is "arch/arm/boot/dts/sama5d2.dtsi" so far. Please check if they sel= ect >>>> CONFIG_PM, then we can make the driver much simpler. >>> >>> Actually the old clock management (for hclk which is the interface >>> clock) is still required as mentioned in the cover letter. Will chang= e >>> the rather misleading description. >> >> Ok. So you can use the code as discussed on >> https://patchwork.kernel.org/patch/9436507/ ? >=20 > Looking at the kernel configuration, it seems like SAMA5D2 platform > selects CONFIG_PM (Wenyou, please confirm). So, it seems like the only > users of this driver always have CONFIG_PM enabled. >=20 > So I guess the best way is to maintain the current code for pm_runtime_= * > and move the clock enable/disable to pm_runtime callbacks. >=20 > Something like this: >=20 > m_can_runtime_resume() > { > clk_prepare_enable(cclk); > clk_prepare_enable(hclk); > } >=20 > m_can_runtime_suspend() > { > clk_disable_unprepare(cclk); > clk_disable_unprepare(hclk); > } >=20 > SET_RUNTIME_PM_OPS(m_can_runtime_suspend, m_can_runtime_resume, NULL) >=20 > static void m_can_start(struct net_device *dev) > { > pm_runtime_get_sync(dev) > ... > } >=20 > static void m_can_stop(struct net_device *dev) > { > ... > pm_runtime_put_sync(dev) > } >=20 > Does that sound okay? If yes, I will go work on the implementation. ACK + error checking. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --KIt3gJ0iOZIS8x9PKgdXdKuDa71mnuNQl-- --mILBW1zXMwVlUrZ8tOETLXDbr33dozHgF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEE4bay/IylYqM/npjQHv7KIOw4HPYFAlpORaoACgkQHv7KIOw4 HPYEpggA0J7mlmUVHxbUACUbX5XlAzSwJZ6O/D59kiMso88Wmxntj04KQocDCoCx Fvr8zMW/C04k/uhkcX8xgNNFbstRi6QTUYPLvu/Qh9n5o1hGMGZaemWPQQ86RUDz OFM5gpVBfKftOx1tLrAWSc2BnS5BVljc96+0lK/htdHGjlIr2YRq9gn7F+Hhm7Fa BOwzpW6wgUUuRr1UyrsTQPCDgIDgD1PUq0l25pRUFEH2or1Ks5uf4vpyEiIMDa19 R2rEd2vPjJibxhnzxf1etgzkrBxEl4DviPi3pSo7x8h2WhFY2+FuYvEi98Wps5Ko 7F6XMEYhXfpy47qu+HTfJJtKl2+Riw== =y6XA -----END PGP SIGNATURE----- --mILBW1zXMwVlUrZ8tOETLXDbr33dozHgF--