From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v2 1/4] can: c_can: fix an interrupt thrash issue with c_can driver Date: Thu, 10 May 2012 21:13:46 +0200 Message-ID: <4FAC136A.6040705@pengutronix.de> References: <1336649657-4152-1-git-send-email-anilkumar@ti.com> <1336649657-4152-2-git-send-email-anilkumar@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig6D819C55322E898BC7BC73A9" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:60415 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756480Ab2EJTOJ (ORCPT ); Thu, 10 May 2012 15:14:09 -0400 In-Reply-To: <1336649657-4152-2-git-send-email-anilkumar@ti.com> Sender: linux-can-owner@vger.kernel.org List-ID: To: AnilKumar Ch Cc: wg@grandegger.com, linux-can@vger.kernel.org, anantgole@ti.com, nsekhar@ti.com This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig6D819C55322E898BC7BC73A9 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 05/10/2012 01:34 PM, AnilKumar Ch wrote: > This patch fixes an interrupt thrash issue with c_can driver. >=20 > In c_can_isr() function interrupts are disabled and enabled only in > c_can_poll() function. c_can_isr() & c_can_poll() both read the > irqstatus flag. However, irqstatus is always read as 0 in c_can_poll() > because all C_CAN interrupts are disabled in c_can_isr(). This causes > all interrupts to be re-enabled in c_can_poll() which in turn causes > another interrupt since the event is not really handled. This keeps > happening causing a flood of interrupts. >=20 > To fix this, read the irqstatus register in isr and use the same cached= > value in the poll function. >=20 > Signed-off-by: AnilKumar Ch Can you or someone else please test this patch on c_can hardware, and add her/his Tested-by? This patch is a stable candidate, isn't it? Acked-by: Marc Kleine-Budde cheers, 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 | --------------enig6D819C55322E898BC7BC73A9 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/ iEYEARECAAYFAk+sE3UACgkQjTAFq1RaXHNeeQCfTeRtvwu6uzWFUH3VY6oYgxqH hwEAmwbrBwsI/qm8N0S75f8PBFz/YbLF =cGAw -----END PGP SIGNATURE----- --------------enig6D819C55322E898BC7BC73A9--