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[71.195.29.92]) by smtp.googlemail.com with ESMTPSA id e22sm25713339iob.66.2019.06.26.06.51.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Jun 2019 06:51:03 -0700 (PDT) Subject: Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver To: Arnd Bergmann Cc: Johannes Berg , Dan Williams , Subash Abhinov Kasiviswanathan , abhishek.esse@gmail.com, Ben Chan , Bjorn Andersson , cpratapa@codeaurora.org, David Miller , DTML , Eric Caruso , evgreen@chromium.org, Ilias Apalodimas , Linux ARM , linux-arm-msm@vger.kernel.org, Linux Kernel Mailing List , linux-soc@vger.kernel.org, Networking , syadagir@codeaurora.org References: <380a6185-7ad1-6be0-060b-e6e5d4126917@linaro.org> <36bca57c999f611353fd9741c55bb2a7@codeaurora.org> <153fafb91267147cf22e2bf102dd822933ec823a.camel@redhat.com> From: Alex Elder Message-ID: <2d40bbcc-1d29-3aa7-e8cb-b0bc5835b8dc@linaro.org> Date: Wed, 26 Jun 2019 08:51:02 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 6/24/19 11:40 AM, Arnd Bergmann wrote: > On Mon, Jun 24, 2019 at 6:21 PM Alex Elder wrote: >> On 6/18/19 2:03 PM, Johannes Berg wrote: >> >>> Really there are two possible ways (and they intersect to some extent). . . . >>> The other is something like IPA or the Intel modem driver, where the >>> device is actually a single (e.g. PCIe) device and just has a single >>> driver, but that single driver offers different channels. >> >> What I don't like about this is that it's more monolithic. It >> seems better to have the low-level IPA or Intel modem driver (or >> any other driver that can support communication between the AP >> and WWAN device) present communication paths that other function- >> specific drivers can attach to and use. > > I did not understand Johannes description as two competing models > for the same code, but rather two kinds of existing hardware that > a new driver system would have to deal with. Based on my understanding of what he said in a message I just responded to, I think you are exactly right. . . . > What we should try to avoid though is a way to add driver private > interfaces that risk having multiple drivers create similar functionality > in incompatible ways. Agreed. -Alex