From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH v10 0/9] Add the I3C subsystem Date: Thu, 15 Nov 2018 16:28:26 +0100 Message-ID: <20181115162826.42b54776@bbrezillon> References: <20181026144333.12276-1-boris.brezillon@bootlin.com> <76b1d15d-232c-d8ba-5eba-8394e71be725@synopsys.com> <20181115135731.25f60990@bbrezillon> <20181115150137.GB4169@kunai> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181115150137.GB4169@kunai> Sender: linux-kernel-owner@vger.kernel.org To: Wolfram Sang Cc: vitor , linux-i2c@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Greg Kroah-Hartman , Arnd Bergmann , Przemyslaw Sroka , Arkadiusz Golec , Alan Douglas , Bartosz Folta , Damian Kos , Alicja Jurasik-Urbaniak , Cyprian Wronka , Suresh Punnoose , Rafal Ciepiela , Thomas Petazzoni , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell List-Id: linux-gpio@vger.kernel.org On Thu, 15 Nov 2018 16:01:37 +0100 Wolfram Sang wrote: > Hi Boris, > > > What we could do though, is expose I3C devices that do not have a > > driver in kernel space, like spidev does. > > ... > > > Mark, Wolfram, Arnd, Greg, any opinion? > > Is there a benefit for having drivers in userspace? My gut feeling is to > encourage people to write kernel drivers. If this is, for some reason, > not possible for some driver, then we have a use case at hand to test > the then-to-be-developed userspace interface against. Until then, I > personally wouldn't waste effort on designing it without a user in > sight. I kind of agree with that. Vitor, do you have a use case in mind for such userspace drivers? I don't think it's worth designing an API for something we don't need (yet). 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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 F3563C43441 for ; Thu, 15 Nov 2018 15:28:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3475223CB for ; Thu, 15 Nov 2018 15:28:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3475223CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388468AbeKPBg5 (ORCPT ); Thu, 15 Nov 2018 20:36:57 -0500 Received: from mail.bootlin.com ([62.4.15.54]:46484 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388019AbeKPBg5 (ORCPT ); Thu, 15 Nov 2018 20:36:57 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id F0D2C20893; Thu, 15 Nov 2018 16:28:37 +0100 (CET) Received: from bbrezillon (aaubervilliers-681-1-13-146.w90-88.abo.wanadoo.fr [90.88.134.146]) by mail.bootlin.com (Postfix) with ESMTPSA id 446A220379; Thu, 15 Nov 2018 16:28:27 +0100 (CET) Date: Thu, 15 Nov 2018 16:28:26 +0100 From: Boris Brezillon To: Wolfram Sang Cc: vitor , linux-i2c@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Greg Kroah-Hartman , Arnd Bergmann , Przemyslaw Sroka , Arkadiusz Golec , Alan Douglas , Bartosz Folta , Damian Kos , Alicja Jurasik-Urbaniak , Cyprian Wronka , Suresh Punnoose , Rafal Ciepiela , Thomas Petazzoni , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven , Linus Walleij , Xiang Lin , linux-gpio@vger.kernel.org, Sekhar Nori , Przemyslaw Gaj , Peter Rosin , Mike Shettel , Stephen Boyd , Mark Brown Subject: Re: [PATCH v10 0/9] Add the I3C subsystem Message-ID: <20181115162826.42b54776@bbrezillon> In-Reply-To: <20181115150137.GB4169@kunai> References: <20181026144333.12276-1-boris.brezillon@bootlin.com> <76b1d15d-232c-d8ba-5eba-8394e71be725@synopsys.com> <20181115135731.25f60990@bbrezillon> <20181115150137.GB4169@kunai> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 Nov 2018 16:01:37 +0100 Wolfram Sang wrote: > Hi Boris, > > > What we could do though, is expose I3C devices that do not have a > > driver in kernel space, like spidev does. > > ... > > > Mark, Wolfram, Arnd, Greg, any opinion? > > Is there a benefit for having drivers in userspace? My gut feeling is to > encourage people to write kernel drivers. If this is, for some reason, > not possible for some driver, then we have a use case at hand to test > the then-to-be-developed userspace interface against. Until then, I > personally wouldn't waste effort on designing it without a user in > sight. I kind of agree with that. Vitor, do you have a use case in mind for such userspace drivers? I don't think it's worth designing an API for something we don't need (yet).