From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: exclusive access to can interface Date: Tue, 08 Jan 2013 10:32:25 +0100 Message-ID: <50EBE7A9.3050809@pengutronix.de> References: <2412937.XVpYjfC7zz@ws-stein> <50EB10F4.6070308@pengutronix.de> <2293513.Wi876mfY7y@ws-stein> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigE3AF4138F257F0280093B199" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:40176 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754135Ab3AHJca (ORCPT ); Tue, 8 Jan 2013 04:32:30 -0500 In-Reply-To: <2293513.Wi876mfY7y@ws-stein> Sender: linux-can-owner@vger.kernel.org List-ID: To: Alexander Stein Cc: linux-can@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigE3AF4138F257F0280093B199 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 01/08/2013 10:23 AM, Alexander Stein wrote: > Hello Marc, >=20 > On Monday 07 January 2013 19:16:20, Marc Kleine-Budde wrote: >> On 01/07/2013 05:52 PM, Alexander Stein wrote: >>> is there a way to get exclusive (write) access to a CAN interface, so= >>> that only one bound socket can write CAN frames on the bus? >> >> No, what's the use case? >=20 > This was a customers request in order to prevent multiple applications = (or=20 > instances) to send CAN frames on a specific CAN interface at the same t= ime=20 > with the very same CAN-IDs. Concurrent reads shall still be allowed! Sending CAN frames is proper serialized by the networking subsystem :) If back to back CAN frames are a problem it seems the design of the application is fishy. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --------------enigE3AF4138F257F0280093B199 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iEYEARECAAYFAlDr56wACgkQjTAFq1RaXHO0NgCePTtKKet6owktiwvcU8lOLb6u sZAAn1iMGdEz06GkCcV+sprcEDDuLecI =rFx2 -----END PGP SIGNATURE----- --------------enigE3AF4138F257F0280093B199--