From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: RFC: [PATCH v2] can: flexcan: Implement errata ERR005829 Date: Tue, 16 Sep 2014 14:58:01 +0200 Message-ID: <541833D9.2060607@pengutronix.de> References: <1409755642-28233-1-git-send-email-david@protonic.nl> <54081940.6060402@pengutronix.de> <20140904104440.5766d764@archvile> <5418238B.6010600@pengutronix.de> <20140916142846.2ae8335c@archvile> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="CsM6huEsf83WItbKp0hMn5wxAhic16tJE" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:36241 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754000AbaIPM6H (ORCPT ); Tue, 16 Sep 2014 08:58:07 -0400 In-Reply-To: <20140916142846.2ae8335c@archvile> Sender: linux-can-owner@vger.kernel.org List-ID: To: David Jander Cc: linux-can@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --CsM6huEsf83WItbKp0hMn5wxAhic16tJE Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 09/16/2014 02:28 PM, David Jander wrote: >>> Please note that if the silicon bug didn't exist, none of the two wri= tes >>> would be necessary. >>> Once you create a quirk for this, how are we supposed to know which >>> versions need this quirk, and which don't? Can we trust the existence= of >>> erratas for the different i.MX Soc's, and should we just go and check= them >>> all? >> >> I had a patch with the quirk, but I removed it, as you suggested, just= >> in case. >=20 > I did not directly suggest to NOT use a quirk, I only had some concerns= =2E In Not directly, but between the lines :D > the meantime I have checked a few of the SoCs for erratas, and found th= is > errata only for i.MX6 and Vybrid VF6xx, which makes me suspect this pro= blem is > unique to IP version 10 (if the IP version table at the beginning of th= e > source-code is to be trusted). We don't even know the IP version of the flexcan core on the vybrid, it has different features than the imx6 one. > OTOH, if you decided to leave the unconditional writes in there, I am f= ine > with that. I don't think they do much harm. >=20 > Is it time to revisit my other patch(es) yet? If so, from where should = I pull > the base? Sorry, no time yet, but I've found another (luckily only a minor) problem with the mailboxes. After sending a RTR frame the TX mailbox gets automatically converted into a RX one. See imx6 data sheet Table 26-5. Message Buffer Code for Tx buffers: > Transmit remote request frame unconditionally once. After > transmission, the MB automatically becomes an Rx Empty MB > with the same ID. I'll prepare a patch. 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 | --CsM6huEsf83WItbKp0hMn5wxAhic16tJE 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 iEYEARECAAYFAlQYM9kACgkQjTAFq1RaXHPwBgCgjRcti2NJwQA9rnVgzYfe3N1o 4qEAoJc5tvb8TU0hOtGGEEcQCuIbl7R2 =9HGZ -----END PGP SIGNATURE----- --CsM6huEsf83WItbKp0hMn5wxAhic16tJE--