From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH v7 03/14] usb: hcd.h: Add OTG to HCD interface Date: Tue, 10 May 2016 11:12:32 +0300 Message-ID: <87twi6ib67.fsf@linux.intel.com> References: <1462191537-10314-1-git-send-email-rogerq@ti.com> <1462191537-10314-4-git-send-email-rogerq@ti.com> <20160506094103.GF32359@shlinux2.ap.freescale.net> <57305C42.90300@ti.com> <20160510031401.GA3748@shlinux2.ap.freescale.net> <57318F19.7000506@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: <57318F19.7000506@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Roger Quadros , Peter Chen Cc: peter.chen@freescale.com, stern@rowland.harvard.edu, gregkh@linuxfoundation.org, dan.j.williams@intel.com, jun.li@freescale.com, mathias.nyman@linux.intel.com, tony@atomide.com, Joao.Pinto@synopsys.com, abrestic@chromium.org, yoshihiro.shimoda.uh@renesas.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, Roger Quadros writes: > On 10/05/16 06:14, Peter Chen wrote: >> On Mon, May 09, 2016 at 12:45:38PM +0300, Roger Quadros wrote: >>> On 06/05/16 12:41, Peter Chen wrote: >>>> On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote: >>>>> The OTG core will use struct otg_hcd_ops to interface >>>>> with the HCD controller. >>>>> >>>>> The main purpose of this interface is to avoid directly >>>>> calling HCD APIs from the OTG core as they >>>>> wouldn't be defined in the built-in symbol table if >>>>> CONFIG_USB is m. >>>>> >>>>> Signed-off-by: Roger Quadros >>>>> Acked-by: Peter Chen >>>> >>>> Roger, after thinking more, I still think current dependency between >>>> OTG, HCD and gadget are too complicated. Since the OTG can't work >>>> if it is built as module, I suggest letting OTG depends on HCD && >>>> USB_GADGET, and it is a boolean, in that case, we don't need to >>>> export any HCD and gadget ops, things will be much simpler. >>>> What's your opinion? >>> >>> How will it work if HCD and USB_GADGET are modules and OTG is built-in? >>> >>=20 >> The OTG will not be compiled at this situation, since it is boolean. >> In fact, like I mentioned at above, OTG or USB function can't work if >> it is built as module. > > Isn't this a limitation? I agree, it should work built-in or module. > As per the current implementation dual role works fine even with both > USB_GADGET and HCD as module. > > In the real world it is unlikely that GADGET and HCD will be built-in. we can't make this assumption, however :-) =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXMZfxAAoJEIaOsuA1yqRE0v0P/1Cq2/hiwSqK5XSEead2gNDT EEqATXrusScuG6mYUuYOHJcFLWVSRk3XY2GlyGrYD+yFNg+rKWigNGGcwSAI53f2 X/EMAtxTwz8QvYPQT3bR52ydwccEXJClzTk/u00Zyo5rgmpwMWh2JFlSQLvP3rP5 BFFSQPk6eG6/q6BP4dzS5f30gZb8cTWVAwr4tJkxbAXobSGlQR+ljn9t9MYwHcgr b23EUv37G8hVZ6Q0oOQnv/D8Y4RAgY5XXVUbnAiu0aIz/0wf3nw4hVX1nbRRUO4l B2UhI7IrK/H7R3BD9Xc6rNZzzhqKxx32tL5Bot3u+K5uavJ1M/BkSIJcWCcyRi6B qZHQx1mDz1GbIMvlzU2YYpqv6y5izRufqt2XwvKyxl6xd/xpIuD55Y5nDThzScT5 sQO9gLmAOT1vbvBtovCDSxnhgJiTmSO390TGQGnWJljbgD5HFA8jfrv/35kI0mnM qgWEWGwrZXTB0/4Rt8rUHXA7wBbwxsdLXlXTC1xEh7inn70TFgBCX5JSVJC1gJDy QeADIHxiUWQ3HFE4BLUo3uVA3IGVkkYkgrrCs6iSGNAUrpsv+9iHYQmvh7lJaUUJ JvOU9gFT3kaH8AaMBTVIh76bmoFsOfmWiZqb/hxctXy9uIZrumqm9n9lcoE/gBnN GPNMIw5Fbrwz7F/p+OtS =ZkuX -----END PGP SIGNATURE----- --=-=-=--