From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v4 4/6] can: flexcan: Consolidate and unify state change handling. Date: Tue, 02 Dec 2014 13:49:24 +0100 Message-ID: <547DB554.8050407@pengutronix.de> References: <3103cd54-1421-4594-855f-7bfca8f4ef49@GRBSR0089.marel.net> <547B7CDD.2080202@grandegger.com> <20141201110923.29602.38961@shannon> <6a5747c2d61b278876b6c3154c6a3130@grandegger.com> <20141201115158.1538.64214@shannon> <20141201122255.3365.66370@shannon> <547CC491.3070705@grandegger.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="hS7cRkDP9OGPTWNE465EiUjmsKCpqacvx" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:56841 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbaLBMtb (ORCPT ); Tue, 2 Dec 2014 07:49:31 -0500 In-Reply-To: <547CC491.3070705@grandegger.com> Sender: linux-can-owner@vger.kernel.org List-ID: To: Wolfgang Grandegger , Andri Yngvason Cc: linux-can@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --hS7cRkDP9OGPTWNE465EiUjmsKCpqacvx Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 12/01/2014 08:42 PM, Wolfgang Grandegger wrote: [...] >> Yes. In any case, the warning interrupt is irrelevant, because we have= to poll >> the state anyway for the other states. Thus the FLEXCAN_HAS_BROKEN_ERR= _STATE >> flag is irrelevant. >=20 > Well, it improves the situation a little bit. But now I understand your= > point. Yes the Flexcan core is buggy in this respect. Yes, just a bit :) This is probably why they added the m_can core on the new imx6 soloX. >> The question that remains is: Should we enable bus error interrupts fo= r all >> flexcan cores or should we ignore the issue and allow the users to wor= k around >> it (if they wish) using the berr-reporting flag? >=20 > Bus error reporting sometimes really harms and therefore I would leave > it as-is. There are also more recent cores and it would be nice to know= n > if they have improved the reporting of state changes further. Anyway, > this issue should be addressed by a separate patch series. >> There is a middle-ground here: We could enable bus error interrupts wh= en we get >> the error-warning interrupt and disable them again when the state has = reached >> error-active again. In that case we would want to keep the BROKEN_ERR_= STATE >> flag. >=20 > Puh, that's far too sophisticated. I agree with Wolfgang. The Bus errors can make a system unresponsive to unusable. There is still the bus error limiting patch lurking around, which works around this problem. 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 | --hS7cRkDP9OGPTWNE465EiUjmsKCpqacvx 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 iQIcBAEBAgAGBQJUfbVUAAoJECte4hHFiupUtnsQAI/mPR+WTFwb2iil8Tb34d3d vfc5zamg8t9VUCoReLj7DL/uezP68nTVygaZ5JkVlhj2l9ETjJKAhIbiBT3C1pqd Eu10hQnBRe87HeIxT/i3xnhmqLK4WbR+DoJFJW7tpCIzae16tvA+x5k4DA2nRHty VlcHgKPpHYwuuaZq/RLZv0tqQSPTwzX2KgjClENsp+tHXzqPP0harjNh5I1vtwlQ rUsyXztW/89zzPRUKXBJ/F8sTocraBXD8KMEST+4tXm5t7nFICehAjbW2xbU2nM7 7r7qEW27DqLh3Q0tLkY5t95w1AsseUXZvWn+c4JhUSKOT0G9ByJbGpiWRREXovuu r1q0XS8FqxRuofXHQYMPBCwN+EeweS8R8QUgu0PGbkHCWC8IqysyuVaQmAX4ioGX Q24j0QTqzVXDbCahh6eCoOveu9ol7Alr2IxeHpHuG2PHkW/s4KWg5spmZ97bLtcU B5gJTHr4vMImaLEGABi4mRd4G8b2aAq2uQhR//Ste1LiQ/egAvlKaw9AIvt/beEm AuEIT/ke98lLfYMVU2jbbJAT97l34ik2RmUyg7n19XsgJJ8fUSni/cQ65zdQE8DT PeC14w1O9d2JqCKstz23RKswmmo7wlYDC+9I5BnU8JVTfI7G9jTahvF6hQ2KT7R1 +jpqvp81kWaaIYbv3HLw =FHSK -----END PGP SIGNATURE----- --hS7cRkDP9OGPTWNE465EiUjmsKCpqacvx--