Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754825AbcCXGwZ (ORCPT ); Thu, 24 Mar 2016 02:52:25 -0400 Received: from mga02.intel.com ([134.134.136.20]:21854 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751132AbcCXGwR (ORCPT ); Thu, 24 Mar 2016 02:52:17 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,383,1455004800"; d="asc'?scan'208";a="72305567" From: Felipe Balbi To: John Youn , John Youn , Roger Quadros Cc: "nsekhar\@ti.com" , "linux-usb\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" Subject: Re: [PATCH 1/2] usb: dwc3: core: Introduce dwc3_device_reinit() In-Reply-To: <56F3376E.8050305@synopsys.com> References: <1458133551-3071-1-git-send-email-rogerq@ti.com> <1458133551-3071-2-git-send-email-rogerq@ti.com> <87r3fah8h3.fsf@intel.com> <87lh5ih6hs.fsf@intel.com> <56EC5452.8030509@synopsys.com> <56F03FD7.30202@synopsys.com> <874mbzyq1l.fsf@intel.com> <56F3376E.8050305@synopsys.com> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/25.0.90.3 (x86_64-pc-linux-gnu) Date: Thu, 24 Mar 2016 08:51:04 +0200 Message-ID: <87d1qkxtbb.fsf@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3547 Lines: 105 --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, John Youn writes: > [ text/plain ] > On 3/21/2016 11:40 PM, Felipe Balbi wrote: >>=20 >> Hi, >>=20 >> John Youn writes: >>> [ text/plain ] >>> On 3/18/2016 12:17 PM, John Youn wrote: >>>> On 3/16/2016 6:56 AM, Felipe Balbi wrote: >>>>> >>>>> heh, +john >>>>> >>>>> Felipe Balbi writes: >>>>>> [ text/plain ] >>>>>> >>>>>> Hi, >>>>>> >>>>>> Roger Quadros writes: >>>>>>> [ text/plain ] >>>>>>> We will need this function for a workaround. >>>>>>> The function issues a softreset only to the device >>>>>>> controller and performs minimal re-initialization >>>>>>> so that the device controller can be usable. >>>>>>> >>>>>>> As some code is similar to dwc3_core_init() take out >>>>>>> common code into dwc3_get_gctl_quirks(). >>>>>>> >>>>>>> We add a new member (prtcap_mode) to struct dwc3 to >>>>>>> keep track of the current mode in the PRTCAPDIR register. >>>>>>> >>>>>>> Signed-off-by: Roger Quadros >>>>>> >>>>>> I must say, I don't like this at all :-p There's ONE known silicon w= hich >>>>>> needs this because of a poor silicon integration which took an IP wi= th a >>>>>> known erratum where it can't be made to work on lower speeds and STI= LL >>>>>> was integrated without a superspeed PHY. >>>>>> >>>>>> There's a reason why I never tried to push this upstream myself ;-) >>>>>> >>>>>> I'm really thinking we might be better off adding a quirk flag to sk= ip >>>>>> the metastability workaround and allow this ONE silicon to set the >>>>>> controller to lower speed. >>>>>> >>>>>> John, can you check with your colleagues if we would ever fall into >>>>>> STAR#9000525659 if we set maximum speed to high speed during driver >>>>>> probe and never touch it again ? I would assume we don't really fall >>>>>> into the metastability workaround, right ? We're not doing any sort = of >>>>>> PM for dwc3... >>>>>> >>> >>> Hi Felipe, >>> >>> Do you mean to keep DCFG.speed to SS and set dwc->maximum_speed to HS? >>> I don't see an issue with that as long as we always ignore >>> dwc->maximum_speed when programming DCFG.speed for all affected >>> versions of the core. As long as the DCFG.speed =3D SS, you should not >>> hit the STAR. >>=20 >> I actually mean changing DCFG.speed during driver probe and never >> touching it again. Would that still cause problems ? >>=20 > > In that case I'm not sure. The engineer who would know is off until > next week so I'll get back to you as soon as I can talk to him about > it. Thank you :-) =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJW845ZAAoJEIaOsuA1yqREx9UQAJst0p2/kv2gzl+SWfA+kXMC c/DHNUGz95WreWy9lhkoD3db+/HRAXioAM+6reDpF09THpbmnN9z0FuNcvYIai1P SoOXHBOKqebI8xDLCLKJXZmhuptxp/nQqS0IjF2TC+mDe2NiIdpDeGADZJ0YIHqm HETDP4AinRckstPMLtIdk47cWirG104RYk4EsRuEwj52UmtR3C7CXDQv0WhlLx0D 8avi/g2jKnWgM2jcmo7MEn55tcXyaiV+N/UJNb1l/taCcvBcEeBnd2j+i4HBsfqP A0b4mJFXiszUjGeTkAMrPPPijb6nIhRzajYKZslnNSh+4bDACIHK35yMPBTqazz/ nzKPHEEyrULnljAemScM1JCLLKyDX/QWozpVhAnyzUxggUggQ/gt6Pb7AbfYlu4S RZuXibMLtHdCjwQmlTh6AKZIMMCbvXEDUsj4nrBmd4uEe6KvGn8SS5A4rsCdHRFb Zs63LfDybrwfq+u7yOyXXnNjJYwQH6noLfV0ffug6AqxDqLGkv7BwFEG1dnvefhD Tf/O9I3lUvqSrfYb4ip7mq5k5NdySn0P8M8P3Ez+xgOpV7kNE+vjsBh97DAo5fNI OZ3fwLzf8aGt0A8onNhswNAL+a3Bu8laBLGbv7sEEQki0X7+uOEkXBCg34FGp/f8 kzt/7oufJfnk2hw+mzkq =LNKL -----END PGP SIGNATURE----- --=-=-=--