From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH] can: flexcan: fix irq flooding by clearing all interrupt sources Date: Tue, 13 Dec 2011 13:53:04 +0100 Message-ID: <4EE74AB0.1080106@pengutronix.de> References: <4EE61928.10608@grandegger.com> <4EE61E3D.2090303@pengutronix.de> <4EE62141.8010305@grandegger.com> <4EE7416E.8070203@grandegger.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig96058EE6412D136C2D476784" Cc: netdev@vger.kernel.org, linux-can@vger.kernel.org, Reuben Dowle , =?ISO-8859-1?Q?Lothar_Wa=DFmann?= To: Wolfgang Grandegger Return-path: In-Reply-To: <4EE7416E.8070203@grandegger.com> Sender: linux-can-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig96058EE6412D136C2D476784 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 12/13/2011 01:13 PM, Wolfgang Grandegger wrote: > On 12/12/2011 04:44 PM, Wolfgang Grandegger wrote: >> On 12/12/2011 04:31 PM, Marc Kleine-Budde wrote: >>> On 12/12/2011 04:09 PM, Wolfgang Grandegger wrote: >>>> As pointed out by Reuben Dowle and Lothar Wa=DFmann, the TWRN_INT, >>>> RWRN_INT, BOFF_INT interrupt sources need to be cleared as well >>>> to avoid interrupt flooding, at least for the Flexcan on i.MX28 >>>> SOCs. Furthermore, the interrupts are only cleared, if really one >>>> of those interrupt sources are pending (which is not the case for >>>> rx and tx done). >>>> >>>> CC: Reuben Dowle >>>> CC: Lothar Wa=DFmann >>>> Signed-off-by: Wolfgang Grandegger >>> >>> Have you tested on mx25/mx35, does it have any negative side effects?= >>> My schedule is full until Friday, sorry cannot test here. >> >> Not yet. But it's not critical. Only the pending interrupt flags are >> cleared. Maybe somebody else out there could do some testing... before= I >> get hold of a MX35PDK board. >=20 > I got my MX35PDK board working and can confirm, that the patch works on= > a i.mx35 as well. My testing also confirms, that the ESR TWRN_INT, > RWRN_INT, FLEXCAN_ESR_BOFF_INT do not function as documented. These > flags do show up once, together with ERR_INT, and then, after clearing,= > never again. Obviously a bug in the Flexcan logic. From the feedback we= > can say, that only the i.MX28 does behave differently (=3D=3Dcorrectly)= =2E All > other seem to work with the current code: >=20 > Flexcan on > - i.mx25 > - i.mx35 > - i.mx53 > - P1010/P1020 I'm adding the patch to linux-can. I think this is a stable candidate for v2.6.39 and newer (mx28 suport was added in 2.6.39). 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 | --------------enig96058EE6412D136C2D476784 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/ iEYEARECAAYFAk7nSrUACgkQjTAFq1RaXHPW5QCghM4MMLJzgNtVWe6TTzKz1X1c AQIAn0qBNnQced8uawYvjV9o8b7vLpeu =yzHp -----END PGP SIGNATURE----- --------------enig96058EE6412D136C2D476784--