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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 29C8FC64E8A for ; Wed, 2 Dec 2020 04:17:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB7CD221E2 for ; Wed, 2 Dec 2020 04:17:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728300AbgLBEQt (ORCPT ); Tue, 1 Dec 2020 23:16:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727590AbgLBEQt (ORCPT ); Tue, 1 Dec 2020 23:16:49 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F751C0613D4 for ; Tue, 1 Dec 2020 20:16:09 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id t18so414088plo.0 for ; Tue, 01 Dec 2020 20:16:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=MmseSE+cXdLssv3A7XwhA62+JeVI67fYqg37Pw8CX+s=; b=CZMlOVhcE+DaJbhEL6v7DShX5B47FyRHV+0mvl4UoFyxQtO4y4pD9uSJPZ/wJWYTR7 ECgglgWPnMOeMbJ8t6x56Ei2QFzkmvV4z5Lia+lXzPsbAU4/12JmHF0EcfmATHVXyRGs yz5q9v6c6fe5T0cRtzlexuG/9VEuwu/sXf4K7+TZw5IxMw4D7RG0hGMpLgmoi6On18DD QLNCkRp6rfONlg7muH2hZHiAXeRs6lP67yMjJVcmDvkAoiEKEIVrXqr8RowOHxCTjLbL kfw2uQGSaiB0oXbRvwYcgQBgCMQnLsATmZZX0aclggv9rASTYk4eDr4vgwKouQTkq4Nx VdEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=MmseSE+cXdLssv3A7XwhA62+JeVI67fYqg37Pw8CX+s=; b=Nsrva0epkQEcGPvaSOkg70ZbLaoZGwYHQ2g9tXpqkJ7OoWA2RwgAoatMq3UEKUrLNn UcsvorVhb9TxUp3oEX9X+IIXpnZ+4OK0iyBRbpGa1y/Jo1K5y60Kdrgv/Ru34xi4CJTp 3HfrbEiW6rK5lF4+TXvXWjcWMpmwJ1Iwjb6T/noqfLK3pY1/N1bQcCVkZgB+riBgWPgl i4A7w5tNDmg+VlhLknGWGL8vpkO7vAS4XnTyRwGEEUOynaWi2mPry3fuoFB+zB2PWTIB g8AShESVuQIHJdt9F1pNicPUulJep2Y9kmqVOx3Frov6rrNNWiCMYXk6f+GN956vBBU9 ZoIw== X-Gm-Message-State: AOAM533mat3GMPL5d3xboBGNysP2qxchZconU/eDLw/5bOSTdffF2xBu SbUz1pQ2w3zL/dWSeTaRVRQg X-Google-Smtp-Source: ABdhPJzRp1eWixG8zA2l2WufQZUMpGtcx2V9TvFvmBE2KJiPdOEDg7cZMVe/o9qpibJZ0jXvsI8WsA== X-Received: by 2002:a17:90a:788e:: with SMTP id x14mr553911pjk.139.1606882568360; Tue, 01 Dec 2020 20:16:08 -0800 (PST) Received: from thinkpad ([103.59.133.81]) by smtp.gmail.com with ESMTPSA id q13sm296402pjq.15.2020.12.01.20.16.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Dec 2020 20:16:07 -0800 (PST) Date: Wed, 2 Dec 2020 09:45:59 +0530 From: Manivannan Sadhasivam To: Jakub Kicinski Cc: Jeffrey Hugo , Hemant Kumar , 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 Subject: Re: [PATCH v13 0/4] userspace MHI client interface driver Message-ID: <20201202041559.GA3241@thinkpad> References: <1606533966-22821-1-git-send-email-hemantk@codeaurora.org> <20201201112901.7f13e26c@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> <20201201120302.474d4c9b@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201201120302.474d4c9b@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 01, 2020 at 12:03:02PM -0800, Jakub Kicinski wrote: > On Tue, 1 Dec 2020 12:40:50 -0700 Jeffrey Hugo wrote: > > 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? > > Yes modems are traditionally highly weird and require some serial > device dance I don't even know about. > > We have proper interfaces in Linux for configuring WiFi which work > across vendors. Having char device access to WiFi would be a step > back. > This is not for configuring the WiFi. This driver is mostly used for modems and the AI accelerator Jeff is working on. But there might be a usecase for WLAN devices as well to collect crash dumps and download fw (typical vendor ways) but having those features are add-ons IMO. So I think we should not be blocked by those usecases. Thanks, Mani