From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751495AbeDEOBA convert rfc822-to-8bit (ORCPT ); Thu, 5 Apr 2018 10:01:00 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:62519 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751312AbeDEOA4 (ORCPT ); Thu, 5 Apr 2018 10:00:56 -0400 From: Patrice CHOTARD To: Hans de Goede , Thierry Reding , Kunihiko Hayashi , Tejun Heo , Matthias Brugger CC: Rob Herring , Mark Rutland , "linux-ide@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mediatek@lists.infradead.org" Subject: Re: [PATCH] ata: ahci-platform: add reset control support Thread-Topic: [PATCH] ata: ahci-platform: add reset control support Thread-Index: AQHTzMQZUjD7lVbUeEu8qjF8anGqFaPyBeiAgAACmoCAAAlQgA== Date: Thu, 5 Apr 2018 14:00:23 +0000 Message-ID: References: <1521768653-11824-1-git-send-email-hayashi.kunihiko@socionext.com> <20180405095429.GA7506@ulmo> <1f7d0738-1963-21c5-c293-e46fb0214ecf@redhat.com> In-Reply-To: <1f7d0738-1963-21c5-c293-e46fb0214ecf@redhat.com> Accept-Language: fr-FR, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.46] Content-Type: text/plain; charset="Windows-1252" Content-ID: <6345CBF3E10ACD43A7A3A801FDDD0447@st.com> Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-04-05_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hans On 04/05/2018 03:27 PM, Hans de Goede wrote: > Hi, > > On 05-04-18 15:17, Patrice CHOTARD wrote: >> Hi Thierry >> >> On 04/05/2018 11:54 AM, Thierry Reding wrote: >>> On Fri, Mar 23, 2018 at 10:30:53AM +0900, Kunihiko Hayashi wrote: >>>> Add support to get and control a list of resets for the device >>>> as optional and shared. These resets must be kept de-asserted until >>>> the device is enabled. >>>> >>>> This is specified as shared because some SoCs like UniPhier series >>>> have common reset controls with all ahci controller instances. >>>> >>>> Signed-off-by: Kunihiko Hayashi >>>> --- >>>>    .../devicetree/bindings/ata/ahci-platform.txt      |  1 + >>>>    drivers/ata/ahci.h                                 |  1 + >>>>    drivers/ata/libahci_platform.c                     | 24 >>>> +++++++++++++++++++--- >>>>    3 files changed, 23 insertions(+), 3 deletions(-) >>> >>> This causes a regression on Tegra because we explicitly request the >>> resets after the call to ahci_platform_get_resources(). >> >> I confirm, we got exactly the same behavior on STi platform. >> >>> >>>   From a quick look, ahci_mtk and ahci_st are in the same boat, >>> adding the >>> corresponding maintainers to Cc. >>> >>> Patrice, Matthias: does SATA still work for you after this patch? This >>> has been in linux-next since next-20180327. >> >> SATA is still working after this patch, but a kernel warning is >> triggered due to the fact that resets are both requested by >> libahci_platform and by ahci_st driver. > > So in your case you might be able to remove the reset handling > from the ahci_st driver and rely on the new libahci_platform > handling instead? If that works that seems like a win to me. Yes, I did a quick test, the reset handling can be removed from our driver. Patrice > > As said elsewhere in this thread I think it makes sense to keep (or re-add > after a revert) the libahci_platform reset code, but make it conditional > on a flag passed to ahci_platform_get_resources(). This way we get > the shared code for most cases and platforms which need special handling > can opt-out. > > Regards, > > Hans > > >> >> Patrice >> >>> >>> Given how this is one of the more hardware-specific bits, perhaps a >>> better way to do this is to move reset handling into a Uniphier driver >>> much like Tegra, Mediatek and ST? >>> >>> That said, I don't see SATA support for any of the Socionext hardware >>> either in the DT bindings or drivers/ata, so perhaps it'd be best to >>> back this out again until we have something that's more well tested? >>> >>> Thierry