Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751601AbaLMRqs (ORCPT ); Sat, 13 Dec 2014 12:46:48 -0500 Received: from mail.kernel.org ([198.145.19.201]:43652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750761AbaLMRqq (ORCPT ); Sat, 13 Dec 2014 12:46:46 -0500 Date: Sat, 13 Dec 2014 18:46:41 +0100 From: Sebastian Reichel To: Grant Likely Cc: NeilBrown , Greg Kroah-Hartman , Mark Rutland , Jiri Slaby , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] TTY: add support for "tty slave" devices. Message-ID: <20141213174640.GA18961@earth.universe> References: <20141211214801.4127.93914.stgit@notabene.brown> <20141211215943.4127.24792.stgit@notabene.brown> <20141212115920.4277AC408F1@trevor.secretlab.ca> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="HcAYCG3uE/tztfnV" Content-Disposition: inline In-Reply-To: <20141212115920.4277AC408F1@trevor.secretlab.ca> 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 --HcAYCG3uE/tztfnV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Fri, Dec 12, 2014 at 11:59:20AM +0000, Grant Likely wrote: > [...] > > --- a/Documentation/devicetree/bindings/serial/of-serial.txt > > +++ b/Documentation/devicetree/bindings/serial/of-serial.txt > > @@ -39,6 +39,10 @@ Optional properties: > > driver is allowed to detect support for the capability even without = this > > property. > > =20 > > +Optional child node: > > +- a platform device listed as a child node will be probed and > > + powered-on whenever the tty is in use (open). > > + >=20 > The biggest concern I have is what happens to nodes that already have > child devices that /don't/ match this use case? It is possible that some > UART nodes already have a child node used to store other data. There are > two ways to handle this; 1) add a new bool property that indicates the > child nodes are tty slave devices, or 2) Make each uart driver > explicitly enable the feature so that driver authors can check if it is > a problem for that device. I personally would suggest #1 because then it > can be enabled in generic code. maybe simple depend on the compatible value? If the UART node has child nodes to store other random data it should not have a compatible value? -- Sebastian --HcAYCG3uE/tztfnV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCgAGBQJUjHt+AAoJENju1/PIO/qaBNkP/RILKWmQxOsqhnr6kxoUGF6t RrGr+NJ8cELaS9fxaAP9EB0mlOQPJeR5Xe8sY0lNEjo2XVvdsOyHQssLTbNaJDM0 LXdU3cN441fhL6h2fUFZG1cUtBDSqj0VcqAkepd9vS+cF8x+NYAz6MKS2drut5Bz /SaG8670aXNLhZN6CgbTXdSrklN/oU6f7aIosSDs5UNCtk3btU1u+F7vDCB4C+q4 0jYDRMfhVK0rtVzwQ6bGzE2+8SfY/rCak8ODAiVxXQ/UQxUR47pJR9TuY3bELGlU 4IrNURia2LS9VKjej8YWx51B8/NiAC6ve/lUL7xp3B2xWuWG+LzaTTLxpsEFVEFX FXeHfcMIplef8ELNAseQE9KzpA7YKpKeEnENamsRYzVlxwvW3t3tjh5hM2bgV7Ir 0QzwmCS0go7n0pXBYwyR+crRWurJPmCLSRJq3EEO42rEQp9XcYiPLBsH4bPIlN7L h4h1yRyw8KH1rL8uY+yAjNFz3/D9K2FAvWPCoswshEYiMuyf4BfI8W6XF8ANPGR8 D1OqKz/Lanf4iZSFtaAlTvX6cEiIn8oj4A+5jKp2IJqMqS0NevLqM2SAZbiIJ+un M0CMaCD3iyyx+jiaZ0M34ufC01N/GdamvxvOVgTo3YyZgBvokDhhDAz8AcTigZhq A/F9BRz1HdmvCb17S9tk =Sw0H -----END PGP SIGNATURE----- --HcAYCG3uE/tztfnV-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/