From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH v2 1/1] usb: gadget: f_fs: Add support for SuperSpeed Mode Date: Wed, 25 Sep 2013 15:40:30 -0500 Message-ID: <20130925204030.GW10746@radagast> References: <1379678152-9617-1-git-send-email-mgautam@codeaurora.org> <52415BAC.6030708@codeaurora.org> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="DHfswzTG6eDt0nli" Return-path: Received: from arroyo.ext.ti.com ([192.94.94.40]:46138 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754787Ab3IYUkk (ORCPT ); Wed, 25 Sep 2013 16:40:40 -0400 Content-Disposition: inline In-Reply-To: <52415BAC.6030708@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Manu Gautam Cc: balbi@ti.com, Jack Pham , pheatwol@codeaurora.org, linux-usb@vger.kernel.org, linux-arm-msm@vger.kernel.org, gregkh@linuxfoundation.org --DHfswzTG6eDt0nli Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, (please avoid top-posting) On Tue, Sep 24, 2013 at 03:00:20PM +0530, Manu Gautam wrote: > Hi Felipe, >=20 > I wanted to mention one point with respect to this patch: Below > changes in the functionfs.h to add ss_count (super speed descriptors > count) in desc_header (which is passed from userspace) make the driver > incompatible with existing userspace applications compiled against old > header file. Let me know if that is acceptable. We are using this > driver with Android for adbd (android debug bridge) and these changes > are required to support adb over Super Speed controllers e.g. DWC3 > along with changed in adbd to pass SS EP and companion descriptors. Good you mentioned, it saves me the trouble of reviewing this patch :-) It's not acceptable to break userspace ABI at all. If you want SuperSpeed support on function fs, we need to figure out a way to do so without breaking userspace. This might mean adding a separate userspace interface to be used with superspeed. While at that, we might want to add a few bytes of reserved, unused space in our structures for situations where we need to add more data into it, just to make it slightly future proof. --=20 balbi --DHfswzTG6eDt0nli Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJSQ0o+AAoJEIaOsuA1yqREvcEP/AkH+tppAheCU1zORKG0ZTWc hEAXfxyBMEc3Dqh4ZC3l9vtEFIomZX96C0KQ9c5tyXu1rHKXLoEgyIS3y4aj2FHU DU2srb6RQXLdpnoWQePZ87Fl6hOJno2JG3wc9oz7jUwITKUUOhzt3gCqkedPft2t PHiwn1ARE8tXxDYjkIX7oR3kXm2q1OFuHXawqytpeVdGL+jPXv6fTxr2pTmjoPNa huw5kwG4ygOXpp9mE+/Hbj0GkW6vzWvo+B7OIvACHV3dT6WsHO6Qarc1h6B6O0Jc fTkfGCsxP/fWAzziL/1OC9lPurhawsqKdyy0pthT9uBP8lS/X1tF9vRjY/XZIup1 aquWJECTDiDr3fP08Z6yz5T8Z3oEWCHNWV65lGU7RicJX+jKlKkuANkWtYo4BQ4P 8h47hm1o1JohdR65lxJeU4Fp8lvJEx01ATdsSIzLQRvqeV7TYZprccKSpmgr7HZl QoURF8fTpicvGInm/o28V5kTQDxVO+A9k75dRW1PAborwQ2SA66fIzutwGsg14Wr n1v3CGMHg+cVGvELMDoUS+jZ1yG1vddttsB7SYjpJB5YrZ3ByBqsb5gO/qAo2g1m X8D4bFlEx2mwqx0ycr0y4eU9pzG3wczzm2it2ob58Cqghb7Pkt5DcnKt8W8jH0RN av09v36anrj1n4LqkjKW =ejmF -----END PGP SIGNATURE----- --DHfswzTG6eDt0nli--