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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, T_DKIMWL_WL_HIGH autolearn=unavailable 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 66333C282CE for ; Tue, 4 Jun 2019 21:29:45 +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 3BA53207E0 for ; Tue, 4 Jun 2019 21:29:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SkF/+ulm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3BA53207E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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=dqwAX4uWMIHUYtHZycq/nGjli9YEmTswK7J6mJ0ny00=; b=SkF/+ulmlQgLr+ no/nDcIRv9kcvhY2WJBdcgnpeHs/ml6+kBOqGxygbWv90VmEL6ZRTew3p+WXn9MplyiQQeL8oYgfW uCjn00qzGhJdQ8EzFGxTgCiXaFObIOY/QjCTrP+cUQ7b4HcVA6p6TLrRAdZ2qY+BFCoUOIV+VlRW9 hhmKJdf4JIKtpVIlL83SrsCJegf+kjK8nzM6p2n5L5vtpmcjyVZ2grfsfgcpyXj5b1tDeBnsMgnrY vvSRSvkf/JbWJ+c17lwBURdSKyYPmXgiSETl5FBXUQ029DBgMXKMpq0LCu1Xct/LpmljitaasZN5C 4//O2jv4dff14/0QZiSg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYGzz-0006v4-Ol; Tue, 04 Jun 2019 21:29:39 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYGzw-0006uG-3h for linux-arm-kernel@lists.infradead.org; Tue, 04 Jun 2019 21:29:37 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AC5872F8BEA; Tue, 4 Jun 2019 21:29:32 +0000 (UTC) Received: from ovpn-112-67.rdu2.redhat.com (ovpn-112-67.rdu2.redhat.com [10.10.112.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5271C5C207; Tue, 4 Jun 2019 21:29:27 +0000 (UTC) Message-ID: <0264d7f9a35430201a89c068bb13c84c622af11a.camel@redhat.com> Subject: Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver From: Dan Williams To: Arnd Bergmann Date: Tue, 04 Jun 2019 16:29:26 -0500 In-Reply-To: References: <20190531035348.7194-1-elder@linaro.org> <065c95a8-7b17-495d-f225-36c46faccdd7@linaro.org> <20190531233306.GB25597@minitux> <040ce9cc-7173-d10a-a82c-5186d2fcd737@linaro.org> User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 04 Jun 2019 21:29:33 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190604_142936_190264_3B71A970 X-CRM114-Status: GOOD ( 23.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: DTML , syadagir@codeaurora.org, Eric Caruso , Networking , linux-arm-msm@vger.kernel.org, Ilias Apalodimas , Linux Kernel Mailing List , evgreen@chromium.org, Bjorn Andersson , abhishek.esse@gmail.com, Linux ARM , Alex Elder , Subash Abhinov Kasiviswanathan , 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, 2019-06-04 at 22:04 +0200, Arnd Bergmann wrote: > On Tue, Jun 4, 2019 at 5:18 PM Dan Williams wrote: > > On Tue, 2019-06-04 at 10:13 +0200, Arnd Bergmann wrote: > > > Can you describe what kind of multiplexing is actually going on? > > > I'm still unclear about what we actually use multiple logical > > > interfaces for here, and how they relate to one another. > > > > Each logical interface represents a different "connection" (PDP/EPS > > context) to the provider network with a distinct IP address and > > QoS. > > VLANs may be a suitable analogy but here they are L3+QoS. > > > > In realistic example the main interface (say rmnet0) would be used > > for > > web browsing and have best-effort QoS. A second interface (say > > rmnet1) > > would be used for VOIP and have certain QoS guarantees from both > > the > > modem and the network itself. > > > > QMAP can also aggregate frames for a given channel > > (connection/EPS/PDP > > context/rmnet interface/etc) to better support LTE speeds. > > Thanks, that's a very helpful explanation! > > Is it correct to say then that the concept of having those separate > connections would be required for any proper LTE modem > implementation, > but the QMAP protocol (and based on that, the rmnet implementation) > is Qualcomm specific and shared only among several generations of > modems from that one vendor? Exactly correct. This is what Johannes is discussing in his "cellular modem APIs - take 2" thread about how this should all be organized at the driver level and I think we should figure that out before we commit to IPA-with-a-useless-netdev that requires rmnets to be created on top. That may end up being the solution but let's have that discussion. > > You mentioned the need to have a common user space interface > for configuration, and if the above is true, I agree that we should > try > to achieve that, either by ensuring rmnet is generic enough to > cover other vendors (and non-QMAP clients), or by creating a > new user level interface that IPA/rmnet can be adapted to. I would not suggest making rmnet generic; it's pretty QMAP specific (but QMAP is spoken by many many modems both SoC, USB stick, and PCIe minicard). Instead, I think what Johannes is discussing is a better approach. A kernel WWAN framework with consistent user API that rmnet/IPA/qmi_wwan/MBIM/QMI/serial/Sierra can all implement. That wouldn't affect the core packet processing of IPA/rmnet but instead: 1) when/how an rmnet device actually gets created on top of the IPA (or qmi_wwan) device AND (one of these two) a) whether IPA creates a netdev on probe OR b) whether there is some "WWAN device" kernel object which userspace interacts with create rmnet channels on top of IPA Dan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel