From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO mode Date: Thu, 10 Dec 2015 13:19:20 +0100 Message-ID: <56696DC8.8020708@pengutronix.de> References: <1431603215-25546-1-git-send-email-bhupesh.sharma@freescale.com> <1431603215-25546-6-git-send-email-bhupesh.sharma@freescale.com> <5554C244.80809@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="GnKnExSCuspSC3PEBEWWpQ8LSFk9rmrj2" Return-path: Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:33590 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814AbbLJMTj (ORCPT ); Thu, 10 Dec 2015 07:19:39 -0500 In-Reply-To: Sender: linux-can-owner@vger.kernel.org List-ID: To: Sharma Bhupesh , "arnd@arndb.de" , "linux-can@vger.kernel.org" Cc: "bhupesh.linux@gmail.com" , "linux-arm-kernel@lists.infradead.org" , Arora Sakar This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --GnKnExSCuspSC3PEBEWWpQ8LSFk9rmrj2 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 12/10/2015 12:05 PM, Sharma Bhupesh wrote: >>> -----Original Message----- >>> From: Marc Kleine-Budde [mailto:mkl@pengutronix.de] >>> Sent: Thursday, May 14, 2015 9:12 PM >>> To: Sharma Bhupesh-B45370; arnd@arndb.de; linux-can@vger.kernel.org >>> Cc: bhupesh.linux@gmail.com; Arora Sakar-B45205; linux-arm- >>> kernel@lists.infradead.org >>> Subject: Re: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO= >>> mode >>> >>> On 05/14/2015 01:33 PM, Bhupesh Sharma wrote: >>>> This patch adds support for non RX-FIFO (legacy) mode in the flexcan= >>>> driver. >>>> >>>> On certain SoCs, the RX-FIFO support might be broken, as a result we= >>>> need to fall-back on the legacy (non RX-FIFO) mode to receive CAN >>>> frames. >>>> >>>> Signed-off-by: Bhupesh Sharma >>>> Signed-off-by: Sakar Arora >>> >>> The non FIFO mode doesn't guarantee the order of the incoming frames,= >>> not does not even try to...this is not acceptable. I'm currently >>> working on a patch by David Jander that brings in non FIFO mode, but >>> tries to keep the order of the frames. >> >> That is already WIP at our end. V3 will contain the same change. >> If you are already working on it, I don't know how to proceed further = as >> we had already v1 of this patchset with the non FIFO mode out since a >> month or so. >=20 > I don't remember seeing a patch from you which supports non-FIFO mode f= or flexcan IP. > Since we now have Freescale LS1021A chip out in the field on which the = FIFO mode broken, > we cannot use the upstream flexcan driver for enabling flexcan IP on th= ese chips. >=20 > Do you still have plans to work on this? Or should I submit my v3 with = in-order reception > supported for rx frames. The problem is, that the current code triggers a ordering issue (at least on the imx6) in non FIFO mode. The frames are not received as the documentation states. If you have access, take a look at "SR# 1-4074792564 : CAN Ordering Issues". It seems the freescale support doesn't have much interest in confirming the issue, nor bringing us in touch with the people who have access to the IP core source to see what's going on. If we have to rely on the timestamps the next logical step is to add sorting by timestamp to the rx-fifo implementation. I'll send a patch series of the current state. 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 | --GnKnExSCuspSC3PEBEWWpQ8LSFk9rmrj2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBCgAGBQJWaW3KAAoJEP5prqPJtc/HEWwH/1avfMrKRh89HdLXYK43uUcK 4/DmI5XpqOO0yE5Y2R1nn2VWWXX3yKCYeFikYpUow2E7/xoYIR4psgYJ5ftFzkVS lfkw/GjxoyJrKg/zmtkh2c266Es5iA4tuMM7QCCCzB9eHwLW7ULvlkPkfsRNJonv TwRNbTVZ4kUrxSaoeCIo6hSzQtZ1+iYoR8z5GkF63JKNma3AFug7yKqMB1T9362w sl4XMcup5VN7zTIYDauRfLusz17U5+/POsM3Gb2SR3PTnKMNvZJ9NXIRCySjBECk G2MkkjxQvXYwFDpICz5gCUZC6+Jt5J2RDjBrgyYx4zdaLb//66HHDsZ+FjKuHdk= =kM3n -----END PGP SIGNATURE----- --GnKnExSCuspSC3PEBEWWpQ8LSFk9rmrj2-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Thu, 10 Dec 2015 13:19:20 +0100 Subject: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO mode In-Reply-To: References: <1431603215-25546-1-git-send-email-bhupesh.sharma@freescale.com> <1431603215-25546-6-git-send-email-bhupesh.sharma@freescale.com> <5554C244.80809@pengutronix.de> Message-ID: <56696DC8.8020708@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/10/2015 12:05 PM, Sharma Bhupesh wrote: >>> -----Original Message----- >>> From: Marc Kleine-Budde [mailto:mkl at pengutronix.de] >>> Sent: Thursday, May 14, 2015 9:12 PM >>> To: Sharma Bhupesh-B45370; arnd at arndb.de; linux-can at vger.kernel.org >>> Cc: bhupesh.linux at gmail.com; Arora Sakar-B45205; linux-arm- >>> kernel at lists.infradead.org >>> Subject: Re: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO >>> mode >>> >>> On 05/14/2015 01:33 PM, Bhupesh Sharma wrote: >>>> This patch adds support for non RX-FIFO (legacy) mode in the flexcan >>>> driver. >>>> >>>> On certain SoCs, the RX-FIFO support might be broken, as a result we >>>> need to fall-back on the legacy (non RX-FIFO) mode to receive CAN >>>> frames. >>>> >>>> Signed-off-by: Bhupesh Sharma >>>> Signed-off-by: Sakar Arora >>> >>> The non FIFO mode doesn't guarantee the order of the incoming frames, >>> not does not even try to...this is not acceptable. I'm currently >>> working on a patch by David Jander that brings in non FIFO mode, but >>> tries to keep the order of the frames. >> >> That is already WIP at our end. V3 will contain the same change. >> If you are already working on it, I don't know how to proceed further as >> we had already v1 of this patchset with the non FIFO mode out since a >> month or so. > > I don't remember seeing a patch from you which supports non-FIFO mode for flexcan IP. > Since we now have Freescale LS1021A chip out in the field on which the FIFO mode broken, > we cannot use the upstream flexcan driver for enabling flexcan IP on these chips. > > Do you still have plans to work on this? Or should I submit my v3 with in-order reception > supported for rx frames. The problem is, that the current code triggers a ordering issue (at least on the imx6) in non FIFO mode. The frames are not received as the documentation states. If you have access, take a look at "SR# 1-4074792564 : CAN Ordering Issues". It seems the freescale support doesn't have much interest in confirming the issue, nor bringing us in touch with the people who have access to the IP core source to see what's going on. If we have to rely on the timestamps the next logical step is to add sorting by timestamp to the rx-fifo implementation. I'll send a patch series of the current state. regards, Marc -- 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 | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 455 bytes Desc: OpenPGP digital signature URL: