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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,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 AB911C71156 for ; Tue, 1 Dec 2020 19:42:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46395206F9 for ; Tue, 1 Dec 2020 19:42:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="pynKYabw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389256AbgLATl4 (ORCPT ); Tue, 1 Dec 2020 14:41:56 -0500 Received: from m42-5.mailgun.net ([69.72.42.5]:45791 "EHLO m42-5.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726213AbgLATlz (ORCPT ); Tue, 1 Dec 2020 14:41:55 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606851690; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=u0ASTfvQ8ODEFBCvRqnSAJ/D/bJXHlTvFNQagCu11Rw=; b=pynKYabwQyCMCsjVLQB9N5wb8X/X5HkmjNMV7fLkpA3IUZIQTmV1/vppx+h64GrM0uK9j0pW gAZAkVgMiduneMU4dkGC4ccn0n1VtP0lNxVptuC9qskx+Q3rE1e+cKtuDKJv9EH8EeNoNiQ1 yOTOdJgKNqBqiJcw3jHdQkNMtIA= X-Mailgun-Sending-Ip: 69.72.42.5 X-Mailgun-Sid: WyI3YTAwOSIsICJsaW51eC13aXJlbGVzc0B2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n09.prod.us-east-1.postgun.com with SMTP id 5fc69c46f4482b01c4cc0b35 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 01 Dec 2020 19:40:54 GMT Sender: jhugo=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 49BF6C433C6; Tue, 1 Dec 2020 19:40:53 +0000 (UTC) Received: from [10.226.59.216] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jhugo) by smtp.codeaurora.org (Postfix) with ESMTPSA id AFD3AC433ED; Tue, 1 Dec 2020 19:40:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AFD3AC433ED Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=jhugo@codeaurora.org Subject: Re: [PATCH v13 0/4] userspace MHI client interface driver To: Jakub Kicinski , Hemant Kumar Cc: manivannan.sadhasivam@linaro.org, gregkh@linuxfoundation.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, bbhatt@codeaurora.org, loic.poulain@linaro.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Kalle Valo References: <1606533966-22821-1-git-send-email-hemantk@codeaurora.org> <20201201112901.7f13e26c@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> From: Jeffrey Hugo Message-ID: Date: Tue, 1 Dec 2020 12:40:50 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201201112901.7f13e26c@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 12/1/2020 12:29 PM, Jakub Kicinski wrote: > On Fri, 27 Nov 2020 19:26:02 -0800 Hemant Kumar wrote: >> This patch series adds support for UCI driver. UCI driver enables userspace >> clients to communicate to external MHI devices like modem and WLAN. UCI driver >> probe creates standard character device file nodes for userspace clients to >> perform open, read, write, poll and release file operations. These file >> operations call MHI core layer APIs to perform data transfer using MHI bus >> to communicate with MHI device. Patch is tested using arm64 based platform. > > Wait, I thought this was for modems. > > Why do WLAN devices need to communicate with user space? > Why does it matter what type of device it is? Are modems somehow unique in that they are the only type of device that userspace is allowed to interact with? However, I'll bite. Once such usecase would be QMI. QMI is a generic messaging protocol, and is not strictly limited to the unique operations of a modem. Another usecase would be Sahara - a custom file transfer protocol used for uploading firmware images, and downloading crashdumps. Off the top of my head, this driver is useful for modems, wlan, and AI accelerators. -- Jeffrey Hugo Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.