From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sharma Bhupesh Subject: RE: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO mode Date: Thu, 10 Dec 2015 12:22:55 +0000 Message-ID: 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> <56696DC8.8020708@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-by2on0114.outbound.protection.outlook.com ([207.46.100.114]:54248 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751162AbbLJMW4 (ORCPT ); Thu, 10 Dec 2015 07:22:56 -0500 In-Reply-To: <56696DC8.8020708@pengutronix.de> Content-Language: en-US Sender: linux-can-owner@vger.kernel.org List-ID: To: Marc Kleine-Budde , "arnd@arndb.de" , "linux-can@vger.kernel.org" Cc: "bhupesh.linux@gmail.com" , "linux-arm-kernel@lists.infradead.org" , Arora Sakar PiAtLS0tLU9yaWdpbmFsIE1lc3NhZ2UtLS0tLQ0KPiBGcm9tOiBNYXJjIEtsZWluZS1CdWRkZSBb bWFpbHRvOm1rbEBwZW5ndXRyb25peC5kZV0NCj4gU2VudDogVGh1cnNkYXksIERlY2VtYmVyIDEw LCAyMDE1IDU6NDkgUE0NCj4gDQo+IE9uIDEyLzEwLzIwMTUgMTI6MDUgUE0sIFNoYXJtYSBCaHVw ZXNoIHdyb3RlOg0KPiA+Pj4gLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0NCj4gPj4+IEZyb206 IE1hcmMgS2xlaW5lLUJ1ZGRlIFttYWlsdG86bWtsQHBlbmd1dHJvbml4LmRlXQ0KPiA+Pj4gU2Vu dDogVGh1cnNkYXksIE1heSAxNCwgMjAxNSA5OjEyIFBNDQo+ID4+PiBUbzogU2hhcm1hIEJodXBl c2gtQjQ1MzcwOyBhcm5kQGFybmRiLmRlOyBsaW51eC1jYW5Admdlci5rZXJuZWwub3JnDQo+ID4+ PiBDYzogYmh1cGVzaC5saW51eEBnbWFpbC5jb207IEFyb3JhIFNha2FyLUI0NTIwNTsgbGludXgt YXJtLQ0KPiA+Pj4ga2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcNCj4gPj4+IFN1YmplY3Q6IFJl OiBbUEFUQ0ggdjIgNS81XSBjYW46IGZsZXhjYW46IEFkZCBzdXBwb3J0IGZvciBub24NCj4gPj4+ IFJYLUZJRk8gbW9kZQ0KPiA+Pj4NCj4gPj4+IE9uIDA1LzE0LzIwMTUgMDE6MzMgUE0sIEJodXBl c2ggU2hhcm1hIHdyb3RlOg0KPiA+Pj4+IFRoaXMgcGF0Y2ggYWRkcyBzdXBwb3J0IGZvciBub24g 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12:22:55 +0000 Subject: [PATCH v2 5/5] can: flexcan: Add support for non RX-FIFO mode In-Reply-To: <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> <56696DC8.8020708@pengutronix.de> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > -----Original Message----- > From: Marc Kleine-Budde [mailto:mkl at pengutronix.de] > Sent: Thursday, December 10, 2015 5:49 PM > > 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. With my current v3, I see no rx-frame ordering issues atleast on LS1021A. I can ask internally about more details on the "SR# 1-4074792564 : CAN Ordering Issues". Regards, Bhupesh