From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752597AbaEGWFK (ORCPT ); Wed, 7 May 2014 18:05:10 -0400 Received: from top.free-electrons.com ([176.31.233.9]:34252 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751777AbaEGWFI (ORCPT ); Wed, 7 May 2014 18:05:08 -0400 Date: Wed, 7 May 2014 17:00:49 -0500 From: Maxime Ripard To: Alan Stern Cc: Emilio Lopez , Mike Turquette , kishon@ti.com, hdegoede@redhat.com, Boris Brezillon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org, kevin.z.m.zh@gmail.com, sunny@allwinnertech.com, shuge@allwinnertech.com, zhuzhenhua@allwinnertech.com, linux-sunxi@googlegroups.com, Boris BREZILLON Subject: Re: [PATCH 4/7] usb: ehci-platform: add optional reset controller retrieval Message-ID: <20140507220049.GC7047@lukather> References: <1399434623-20383-5-git-send-email-maxime.ripard@free-electrons.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7gGkHNMELEOhSGF6" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --7gGkHNMELEOhSGF6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 07, 2014 at 10:25:55AM -0400, Alan Stern wrote: > On Tue, 6 May 2014, Maxime Ripard wrote: >=20 > > From: Boris BREZILLON > >=20 > > On the Allwinner's A31 SoC the reset line connected to the EHCI IP has = to > > be deasserted for the EHCI block to be usable. > >=20 > > Add support for an optional reset controller that will be deasserted on > > power off and asserted on power on. > >=20 > > Signed-off-by: Boris BREZILLON > > Signed-off-by: Maxime Ripard >=20 > Is this really a _reset_ line? That is, when you assert the reset=20 > line, does it actually reset the EHCI controller, or does it merely=20 > leave the controller in a partially powered-down state? It actually resets the whole controller. > The difference is important. During suspend, the controller is > supposed to remember the state of the port connections as well as other > settings. If it doesn't, the controller and all attached USB devices > will have to be reinitialized every time the controller resumes, which > will increase the latency. So you're saying that we should move this to the probe then? Thanks, Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --7gGkHNMELEOhSGF6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQIcBAEBAgAGBQJTaq0RAAoJEBx+YmzsjxAgi4AP/02ZdeNJtibPjwsygnQAnJkD ndwlSTxAPpWn0NXQg5KltvQHNndUyI1GZmqYRT2HfHWpJn9jEWdwII+C+Ny4QpWo mASD5mPQSx/c0aePDibEtIQ8lAIxZcwYOx30C5WUex3h/avykBoTwN2dv6hBRWOt EXUmZN057pFcK9/d+b5jCbGLoY8wiSGa6SjojFb64N36iIqCSMLQyHPU6SRt9/nv UzMDCIEVMMfeiJ59EmmsMBfcxhP4BM7irmUH8lgwfriE2X+2pGDaZUNI/le9tiyR E1pTFZd1D2zS+Mq9TjMGqiAfbFkAMnRP3RFb1adjBmFmTxjgLKC7QIkQ0YZyZ7gx lQsy+JukpueEwh00pQp7fZs5P4wc3y/8BKDNYYSWSTORG11MztAEntoUHDq/ou7F CrW68Guw5GXg+OhHuEyupqUKm7KY2zWDbyxMNoq/eE9AQRFsFxOcEKotU8rtGt5I HKflfuHlKTNefFfLWLQIDICy1NnG+Egbo24ZP61Y7/1bStnwfae+cBUbrrAWpdhw xdNMkmMHaA0yqsBBL6fl7TwAvHnJHDrYlAGJH8sp+7wRbAqkugQbJgmc5vUcng5w VKUTJP0v5XvRo4VCfEXvZ9LA54eT+6VslL7fOrebW6SprodxumxyjtkWKCG43spy bCHuoc1ilh4GexJ6uwhu =rEfp -----END PGP SIGNATURE----- --7gGkHNMELEOhSGF6--