From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8A91C433FF for ; Mon, 29 Jul 2019 10:17:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B82922070D for ; Mon, 29 Jul 2019 10:17:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kapsi.fi header.i=@kapsi.fi header.b="tFKJc9Yt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387426AbfG2KRE (ORCPT ); Mon, 29 Jul 2019 06:17:04 -0400 Received: from mail.kapsi.fi ([91.232.154.25]:41637 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbfG2KRE (ORCPT ); Mon, 29 Jul 2019 06:17:04 -0400 X-Greylist: delayed 1870 seconds by postgrey-1.27 at vger.kernel.org; Mon, 29 Jul 2019 06:17:03 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=nAOqsxTyQ4gYltZdfhxaj3SXIvjncVO2sE1nkzwLk4E=; b=tFKJc9Yt/mc9zFIxobPi3ypDnT FuFFk4dfGUY/bNKduZtIu8/UzABRB1Mha/OY/Ka8bOZirm+sTiODILWjX4eI+TPKltxOPPiQlbBWf lcHn1Z0FzpIT4jJpnngoKPRCpZkJSiAYOKF0inIIvZbjXYs/JEN1xIMWhsW+oqqxsCRG8jjpVYtwH xIu5UVDbY4tj1Vq8rYyxrZzG8FuW5l7NvTl6UJXLmzrim4oCDDlYgIVT73gKTNknPKxmV2BKUwywp /lusWQQUCCBhcY3HRSvCHguQ35UYGPRHyFfrjCxbM/1CiWrqTaSa0O7WpHNTzhkMPxg/krGIShmVI 9u4ITH2A==; Received: from [193.209.96.43] (helo=[10.21.26.179]) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1hs2Dn-0007rJ-W0; Mon, 29 Jul 2019 12:45:36 +0300 Subject: Re: [PATCH net-next 3/3] net: stmmac: Introducing support for Page Pool To: Jon Hunter , Jose Abreu , Lars Persson , Ilias Apalodimas Cc: Joao Pinto , Alexandre Torgue , Maxime Ripard , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-stm32@st-md-mailman.stormreply.com" , Chen-Yu Tsai , Maxime Coquelin , linux-tegra , Giuseppe Cavallaro , "David S . Miller" , "linux-arm-kernel@lists.infradead.org" References: <20190722101830.GA24948@apalos> <11557fe0-0cba-cb49-0fb6-ad24792d4a53@nvidia.com> <2ad7bf21-1f1f-db0f-2358-4901b7988b7d@nvidia.com> <8093e352-d992-e17f-7168-5afbd9d3fb3f@nvidia.com> From: Mikko Perttunen Message-ID: <299d1803-fc5c-9298-3d10-582e76b47a9e@kapsi.fi> Date: Mon, 29 Jul 2019 12:45:25 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 193.209.96.43 X-SA-Exim-Mail-From: cyndis@kapsi.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My understanding is that Tegra186 does not have DMA coherency, but Tegra194 does. Mikko On 23.7.2019 16.34, Jon Hunter wrote: > > On 23/07/2019 13:51, Jose Abreu wrote: >> From: Jon Hunter >> Date: Jul/23/2019, 12:58:55 (UTC+00:00) >> >>> >>> On 23/07/2019 11:49, Jose Abreu wrote: >>>> From: Jon Hunter >>>> Date: Jul/23/2019, 11:38:33 (UTC+00:00) >>>> >>>>> >>>>> On 23/07/2019 11:07, Jose Abreu wrote: >>>>>> From: Jon Hunter >>>>>> Date: Jul/23/2019, 11:01:24 (UTC+00:00) >>>>>> >>>>>>> This appears to be a winner and by disabling the SMMU for the ethernet >>>>>>> controller and reverting commit 954a03be033c7cef80ddc232e7cbdb17df735663 >>>>>>> this worked! So yes appears to be related to the SMMU being enabled. We >>>>>>> had to enable the SMMU for ethernet recently due to commit >>>>>>> 954a03be033c7cef80ddc232e7cbdb17df735663. >>>>>> >>>>>> Finally :) >>>>>> >>>>>> However, from "git show 954a03be033c7cef80ddc232e7cbdb17df735663": >>>>>> >>>>>> + There are few reasons to allow unmatched stream bypass, and >>>>>> + even fewer good ones. If saying YES here breaks your board >>>>>> + you should work on fixing your board. >>>>>> >>>>>> So, how can we fix this ? Is your ethernet DT node marked as >>>>>> "dma-coherent;" ? >>>>> >>>>> TBH I have no idea. I can't say I fully understand your change or how it >>>>> is breaking things for us. >>>>> >>>>> Currently, the Tegra DT binding does not have 'dma-coherent' set. I see >>>>> this is optional, but I am not sure how you determine whether or not >>>>> this should be set. >>>> >>>> From my understanding it means that your device / IP DMA accesses are coherent regarding the CPU point of view. I think it will be the case if GMAC is not behind any kind of IOMMU in the HW arch. >>> >>> I understand what coherency is, I just don't know how you tell if this >>> implementation of the ethernet controller is coherent or not. >> >> Do you have any detailed diagram of your HW ? Such as blocks / IPs >> connection, address space wiring , ... > > Yes, this can be found in the Tegra X2 Technical Reference Manual [0]. > Unfortunately, you need to create an account to download it. > > Jon > > [0] https://developer.nvidia.com/embedded/dlc/parker-series-trm >