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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=ham 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 636E0C31E5B for ; Tue, 18 Jun 2019 21:02:37 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3A0A220863 for ; Tue, 18 Jun 2019 21:02:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="scVnhYnI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A0A220863 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sipsolutions.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lO2MSeRK0aEiyp7KtQvFSLQVPT+GoHoTh6skicOLThs=; b=scVnhYnIHIEpLp wN9cWDy8MUeszeOI47BCSstT30IikA/dtLfBwkWlfnx8PZnOJ7UflYSpVxxLJL6/i+MyatId1ZHRp TZoWyFfoLnEDj9O5cj6jfiqKy8ZdIKaox0llSB8fDTEoitF6L5L0D8okDGssO2y4GDMbeheNFDK52 1qIsg1Exb6s2h37PN4PchPpZCzapIe7UjgIddaRm0BWSRdJ0YLnzonNTCBPTW555RJdaVnl+2LQwn YK5JsMioG/YWmd6N0uIQdYWewMK9ZxVJDsRoGNM5FcWy6Pmhh3Y2EnB6jDlX5CPRb0Z7ihAz39WKW TwS+psqV789BLbRSV8Hw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hdLFU-0004w8-IR; Tue, 18 Jun 2019 21:02:36 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:191:4433::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hdLFR-0004vJ-QK for linux-arm-kernel@lists.infradead.org; Tue, 18 Jun 2019 21:02:35 +0000 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hdLFE-0007LA-Ng; Tue, 18 Jun 2019 23:02:20 +0200 Message-ID: <6e7f0fb2f85d5062a9e23d37c47d311e10aa4624.camel@sipsolutions.net> Subject: Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver From: Johannes Berg To: Arnd Bergmann Date: Tue, 18 Jun 2019 23:02:18 +0200 In-Reply-To: (sfid-20190618_225543_624686_3B7D51E7) References: <380a6185-7ad1-6be0-060b-e6e5d4126917@linaro.org> <066e9b39f937586f0f922abf801351553ec2ba1d.camel@sipsolutions.net> <613cdfde488eb23d7207c7ba6258662702d04840.camel@sipsolutions.net> (sfid-20190618_225543_624686_3B7D51E7) X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190618_140233_858750_5B98CEF4 X-CRM114-Status: GOOD ( 18.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: DTML , syadagir@codeaurora.org, Eric Caruso , Dan Williams , linux-arm-msm@vger.kernel.org, abhishek.esse@gmail.com, Linux Kernel Mailing List , evgreen@chromium.org, Bjorn Andersson , Ilias Apalodimas , Linux ARM , Alex Elder , Subash Abhinov Kasiviswanathan , Networking , linux-soc@vger.kernel.org, David Miller , cpratapa@codeaurora.org, Ben Chan Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2019-06-18 at 22:55 +0200, Arnd Bergmann wrote: > On Tue, Jun 18, 2019 at 10:36 PM Johannes Berg > wrote: > > > > On Tue, 2019-06-18 at 21:59 +0200, Arnd Bergmann wrote: > > > > > > From my understanding, the ioctl interface would create the lower > > > netdev after talking to the firmware, and then user space would use > > > the rmnet interface to create a matching upper-level device for that. > > > This is an artifact of the strong separation of ipa and rmnet in the > > > code. > > > > Huh. But if rmnet has muxing, and IPA supports that, why would you ever > > need multiple lower netdevs? > > From my reading of the code, there is always exactly a 1:1 relationship > between an rmnet netdev an an ipa netdev. rmnet does the encapsulation/ > decapsulation of the qmap data and forwards it to the ipa netdev, > which then just passes data through between a hardware queue and > its netdevice. I'll take your word for it. Seems very odd, given that the whole point of the QMAP header seems to be ... muxing? > [side note: on top of that, rmnet also does "aggregation", which may > be a confusing term that only means transferring multiple frames > at once] Right, but it's not all that much interesting in the context of this discussion. > Sure, I definitely understand what you mean, and I agree that would > be the right way to do it. All I said is that this is not how it was done > in rmnet (this was again my main concern about the rmnet design > after I learned it was required for ipa) ;-) :-) Well, I guess though if the firmware wants us to listen to those on/off messages we'll have to do that one way or the other. Oh. Maybe it's just *because* rmnet is layered on top, and thus you fundamentally cannot do flow control the way I described - not because you have multiple session on the same hardware ring, but because you abstracted the hardware ring away too much ... johannes _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel