From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752815AbcE0LR6 (ORCPT ); Fri, 27 May 2016 07:17:58 -0400 Received: from sauhun.de ([89.238.76.85]:47364 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083AbcE0LR4 (ORCPT ); Fri, 27 May 2016 07:17:56 -0400 Date: Fri, 27 May 2016 13:17:45 +0200 From: Wolfram Sang To: Erico Nunes Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] i2c-dev: switch from register_chrdev to cdev API Message-ID: <20160527111745.GA1663@katana> References: <1462301143-6084-1-git-send-email-erico.nunes@datacom.ind.br> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bg08WKrSYDhXBjb5" Content-Disposition: inline In-Reply-To: <1462301143-6084-1-git-send-email-erico.nunes@datacom.ind.br> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 03, 2016 at 03:45:43PM -0300, Erico Nunes wrote: > i2c-dev had never moved away from the older register_chrdev interface to > implement its char device registration. The register_chrdev API has the > limitation of enabling only up to 256 i2c-dev busses to exist. >=20 > Large platforms with lots of i2c devices (i.e. pluggable transceivers) > with dedicated busses may have to exceed that limit. > In particular, there are also platforms making use of the i2c bus > multiplexing API, which instantiates a virtual bus for each possible > multiplexed selection. >=20 > This patch removes the register_chrdev usage and replaces it with the > less old cdev API, which takes away the 256 i2c-dev bus limitation. > It should not have any other impact for i2c bus drivers or user space. >=20 > This patch has been tested on qemu x86 and qemu powerpc platforms with > the aid of a module which adds and removes 5000 virtual i2c busses, as > well as validated on an existing powerpc hardware platform which makes > use of the i2c bus multiplexing API. > i2c-dev busses with device minor numbers larger than 256 have also been > validated to work with the existing i2c-tools. >=20 > Signed-off-by: Erico Nunes Applied to for-next, thanks! I'll try to still get it into v4.7. --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXSCzZAAoJEBQN5MwUoCm2C+AP/3B6Joh27f0szqqsgYcgYUpR WgcR43JBTo0eO4tXOuBiBxXYHI4yxbYUhCITvO/g8ywYB3SSsvZ7T5ffVOta2MaN G9xLn+pc9S4U9zvVhbxSplV9CH32pRLLkmvkqv8YmNj4hLG6rXVPxzOtsdX3rooP aPOCM30o78Hixb4dIOGYPFPRUjdV1t7DjokTp+rlVjknXuSpS08SToKKYumIDExq viXFrBZwwoFdIqrhxlBxPanhAhjM+GZMP6bT6flnInjhR162u1a+QZLKOLIitanS /FppjmwsiUCWZaR7kCI/qv/QvF5WLW/EgMcxBNh1lWhxd93YfIshMkk2OZeuIlXU lMuJB1oQd35jnNoi1PgS5HO995PoNECjLVhLw7KHuEgnlQ2NGAP2FY1VmP/RmO4Y 5zS33+ltCWJAoN6eMsKCtsGrtQ8huxZbfF3TSqcn7N+XqdjgCpMrutL6rsYiWWq7 PEaqIHkriJW24aKxUzL53gl1sVRx9ltXr0C+GbMMdTONtZKWgnsm7+20gCqy72pu OIy1Njs8MVoQw2Z+slOjJjrpshGpBU5jYCFPdYt5ZGMCzRcBrKdwZJFqyMoMxgnB yJW4ZsLlClIXKJfa/F7iHutnJDL6I2+h5LS/rFwUVWlxpPZMkz5sQVcTxldiryTS z93IqiUcc11/YolVyudh =gK9r -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5--