From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964855AbaH0T2m (ORCPT ); Wed, 27 Aug 2014 15:28:42 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:59903 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935548AbaH0T2k (ORCPT ); Wed, 27 Aug 2014 15:28:40 -0400 Date: Wed, 27 Aug 2014 14:28:25 -0500 From: Felipe Balbi To: Vivek Gautam CC: Bartlomiej Zolnierkiewicz , Felipe Balbi , Olof Johansson , Kukjin Kim , Kyungmin Park , "linux-samsung-soc@vger.kernel.org" , Linux USB Mailing List , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] usb: dwc3: exynos: remove usb_phy_generic support Message-ID: <20140827192825.GJ6347@saruman.home> Reply-To: References: <2141307.zYQLjP6V6U@amdc1032> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gBdJBemW82xJqIAr" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --gBdJBemW82xJqIAr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Wed, Aug 27, 2014 at 11:42:25PM +0530, Vivek Gautam wrote: > On Wed, Aug 27, 2014 at 1:22 PM, Bartlomiej Zolnierkiewicz > wrote: > > dwc3 driver is using the new Exynos5 SoC series USB DRD PHY driver > > (PHY_EXYNOS5_USBDRD which selects GENERIC_PHY) as can be seen by > > looking at the following commits: > > > > 7a4cf0fde054 ("ARM: dts: Update DWC3 usb controller to use new > > phy driver for exynos5250") > > > > f070267b5fc1 ("ARM: dts: Enable support for DWC3 controller for > > exynos5420") > > > > Thus remove unused usb_phy_generic support from dwc3 Exynos glue > > layer. > > > > [ The code that is being removed is harmful in the context of > > multi_v7_defconfig and enabling "EHCI support for Samsung > > S5P/EXYNOS SoC Series" (USB_EHCI_EXYNOS) + "OHCI support for > > Samsung S5P/EXYNOS SoC Series" (USB_OHCI_EXYNOS) because "EHCI > > support for OMAP3 and later chips" (USB_EHCI_HCD_OMAP) selects > > "NOP USB Transceiver Driver" (NOP_USB_XCEIV). NOP USB driver > > attaches itself to usb_phy_generic platform devices created by > > dwc3 Exynos glue layer and later causes Exynos EHCI driver to > > fail probe and Exynos OHCI driver to hang on probe (as observed > > on Exynos5250 Arndale board). ] >=20 > The issue with EHCI and OHCI on exynos platforms is that until now > they also request > usb-phy and only later if they don't find one, they go ahead and get a > 'phy' generic. >=20 > Fortunately we missed this issue with exynos_defconfig, and as you rightly > mentioned with multi_v7_defconfig, the NOP_USB_XCEIV gets enabled and > EHCI and OHCI exynos get no-op usb-phy, which actually blocks EHCI/OHCI f= rom > initializing the real PHYs. right, when I added PHY support to dwc3 I expected people to remote NOP transceivers from their glue layers after they had proper PHY drivers available. > This issue is resolved with patches: > [PATCH v2 1/2] usb: host: ehci-exynos: Remove unnecessary usb-phy support > [PATCH v2 2/2] usb: host: ohci-exynos: Remove unnecessary usb-phy support > wherein we are completely removing the usb-phy support from ehci/ohci-exy= nos. > So with these patches we should not see the issue mentioned by you. >=20 > Now for the DWC3 part, the usb-phy part was added to use register two > separate no-op-xceivers of USB2_PHY type and USB3_PHY type, > so that platforms with no separate PHY can still be able to use dwc3. correct. --=20 balbi --gBdJBemW82xJqIAr Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJT/jFZAAoJEIaOsuA1yqRE5fEP/RKzYqbF5AaTr9JeUjDCfBrR IHgV4wPDMfBdajroYZVM+dvEzePFwrEDcaATI+jnXnO6op0tgdmfklthhyopxfnH 5P7I0BnHiPlBVnAOaXJGchqmvr5OokabRy0rdXLbD0tacVCOXvBPPOjG5Qqjz9VR Im0CG05N35exacMcld8nl/iRZ35pjxucMeopBpB6pYkA5shQ28OdeRAFe8iXjNC8 /IQDSPvgxn2s8ILq+xiSx9JWKjDICrwFsIThA92D+AG9SkVGokbnMCeNhfPRuEch GywfhLOikQlIlB5KJ8v3IiVMEaW6TEPbgd+aKJpCpsrERvJqtxVPaas4yPSAE2f0 UHw48HVW+ngQ66acBcfbYiUJcfyp3u82S8Zq+0bvXK0tyXOuQ9cSSPcQN7uljw0N 8STUExqYuwMf5mBTTfdAvHULr6lPHwMLAk0kB9W1OD0e34Ss+Mf+BN26ezWXx/dL q3zmfNRDMdr1o4tOo4tKQC2D3EEzef/QFmAKYJEm9EGPhw5Ftj2gbBfC2c3nA06A vsyyu1ExfaqOWhT2/5ZLrm3EvZMm2kSQT5k+6DLcnFWX1zb3Z5J597O4BuoAy/Kf y4As3GsuNwVI2oMlzob0780DUoCFpnVmuLtFrK56MTjC6k0ZPIdWI/45OdMIyC5o mIcxFCFU2z4vFI3hqJg2 =/rUU -----END PGP SIGNATURE----- --gBdJBemW82xJqIAr--