From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver Date: Tue, 04 Jun 2019 10:21:41 -0500 Message-ID: References: <20190531035348.7194-1-elder@linaro.org> <065c95a8-7b17-495d-f225-36c46faccdd7@linaro.org> <3b1e12b145a273dd3ded2864d976bdc5fa90e68a.camel@redhat.com> <87f98f81-8f77-3bc5-374c-f498e07cb1bd@linaro.org> <0fc29577a5c69530145b6095fa1ac1a51949ba8e.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Subash Abhinov Kasiviswanathan Cc: Alex Elder , Arnd Bergmann , David Miller , Bjorn Andersson , Ilias Apalodimas , evgreen@chromium.org, Ben Chan , Eric Caruso , cpratapa@codeaurora.org, syadagir@codeaurora.org, abhishek.esse@gmail.com, Networking , DTML , Linux Kernel Mailing List , linux-soc@vger.kernel.org, Linux ARM , linux-arm-msm@vger.kernel.org List-Id: devicetree@vger.kernel.org On Mon, 2019-06-03 at 13:04 -0600, Subash Abhinov Kasiviswanathan wrote: > > > I can't (or won't) comment right now on whether IPA needs its own > > > netdev for rmnet to use. The IPA endpoints used for the modem > > > network interfaces are enabled when the netdev is opened and > > > disabled when closed. Outside of that, TX and RX are pretty > > > much immediately passed through to the layer below or above. > > > IPA currently has no other net device operations. > > > > I don't really have issues with the patchset underneath the netdev > > layer. I'm interested in how the various bits present themselves to > > userspace, which is why I am trying to tie this in with Johannes' > > conversation about WWAN devices, netdevs, channels, and how the > > various > > drivers present API for creating data channels that map to > > different > > modem contexts. > > > > So let me rephrase. If the control plane has set up the default > > context > > and sent a QMI Start Network message (or the network attached the > > default one) and the resulting IP details are applied to the IPA > > netdev > > can things just start sending data? Or do we need to create an > > rmnet on > > top to get that working? > > > > Dan > > Hi Dan > > All data from the hardware will have the MAP headers. > We still need to create rmnet devs over the IPA netdev and use it > for > the > data path. > The IPA netdev will pass on the packets which it receives from the > hardware > and queue it to network stack where it will be intercepted by the > rmnet rx handler. Ok, so IPA only needs a netdev so that rmnet has something to send/receive packets to/from? This gets even closer to the discussion in "cellular modem driver APIs - take 2" from last week. Dan