From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v4 1/1] can: add pruss CAN driver. Date: Mon, 23 May 2011 10:23:15 +0200 Message-ID: <4DDA1973.4090309@pengutronix.de> References: <1303474267-6344-1-git-send-email-subhasish@mistralsolutions.com> <4DCB88A4.2010901@grandegger.com> <4DCBF1B6.6000104@hartkopp.net> <201105221230.56243.arnd@arndb.de> <4DD9FCFC.10803@hartkopp.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4242707717062897747==" Cc: sachi-EvXpCiN+lbve9wHmmfpqLFaTQe2KTcn/@public.gmane.org, davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org, Arnd Bergmann , Subhasish Ghosh , nsekhar-l0cyMroinI0@public.gmane.org, open list , CAN NETWORK DRIVERS , Alan Cox , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, m-watkins-l0cyMroinI0@public.gmane.org, Wolfgang Grandegger To: Oliver Hartkopp Return-path: In-Reply-To: <4DD9FCFC.10803-fJ+pQTUTwRTk1uMJSBkQmQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============4242707717062897747== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigC295372533A9F99782DE402D" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigC295372533A9F99782DE402D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 05/23/2011 08:21 AM, Oliver Hartkopp wrote: [...] > In 'real world' CAN setups you'll never see 21.000 CAN frames per secon= d (and > therefore 21.000 irqs/s) - you are usually designing CAN network traffi= c with > less than 60% busload. So interrupt rates somewhere below 1000 irqs/s c= an be > assumed. >=20 > From what i've seen so far a 3-4 messages rx FIFO and NAPI support just= make it. >=20 > @Marc/Wolfgang: Would this be also your recommendation for a CAN contro= ller > design that supports SocketCAN in the best way? If you have a rx FIFO NAPI is the way to go. For a single mailbox it adds overhead, if you can read the CAN frame in the interrupt handler. The error messages should probably generated from NAPI, too. Especially the I'm-the-only-CAN-node-on-the-net-and-get-no-ACK error message. However IIRC David said that every new driver should implement NAPI. > As the Linux network stack supports hardware timestamps too, this could= be an > additional (optional!) feature. regards, 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 | --------------enigC295372533A9F99782DE402D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk3aGXYACgkQjTAFq1RaXHOi6ACfQ4kY0ukWKfqwYANq0x5mV3gD lt8AoJjkRhJ0UWdPQ/dpzOA6WC4zJk6w =v0Gq -----END PGP SIGNATURE----- --------------enigC295372533A9F99782DE402D-- --===============4242707717062897747== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Socketcan-core mailing list Socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org https://lists.berlios.de/mailman/listinfo/socketcan-core --===============4242707717062897747==--