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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 BFF37C4167B for ; Thu, 16 Sep 2021 17:51:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7BD86120E for ; Thu, 16 Sep 2021 17:51:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357020AbhIPRvU (ORCPT ); Thu, 16 Sep 2021 13:51:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:57064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355808AbhIPRmJ (ORCPT ); Thu, 16 Sep 2021 13:42:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 893AF6327B; Thu, 16 Sep 2021 16:54:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631811261; bh=ymQzYeMkLSk6v7VLwAJT4gG7bsnwMv9w8QyoD1DrwQI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QyOh7q7xkv+WP1e95rr6xb6oYW92hu5MI8ZsvQkDdmGHv6C9EkbpoiPQGOVZbzWiD XmmRtdIoz0tQAcACw5mp66RhQBm1jigAlpaMZNih9teUVJUlNWJwAtrYaHI7dyAfL6 OsUkrawTFYPGMPo+ZJ9zn8y6J+uO2fxA0DbjKfUQ= Date: Thu, 16 Sep 2021 18:05:16 +0200 From: Greg KH To: Min Li Cc: "arnd@arndb.de" , "derek.kiernan@xilinx.com" , "dragan.cvetic@xilinx.com" , "linux-kernel@vger.kernel.org" , "lee.jones@linaro.or" Subject: Re: [PATCH misc v2 2/2] misc: Add Renesas Synchronization Management Unit (SMU) support Message-ID: References: <1631731629-20862-1-git-send-email-min.li.xe@renesas.com> <1631731629-20862-2-git-send-email-min.li.xe@renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 16, 2021 at 03:54:52PM +0000, Min Li wrote: > > > > Please put that link in the changelog comment and in the .c code as well so > > that people know where to find it. > > > > > > > > > > Why is this new api not a standard one? > > > > > > > > > > There is no actual standard for the GNSS assisted partial timing > > > support (APTS) In terms of Linux kernel API > > > > Then make one! :) > > Yes it is on our roadmap to do that for next release Please do it for this kernel api, otherwise you have to support this for the next 20+ years as-is :( > > Why not just do this all from userspace then? You can have spi/i2c > > userspace code, right? Why does this have to be a kernel driver? > > > We used to do everything in userspace. But since PHC (ptp hardware clock) came along, we decided > to move the driver part to kernel. Please take a look at drivers/ptp/ptp_clockmatrix.c for reference. > Recently, we have some functions like APTS that doesn't belong to PTP or anything else so we have to split those functions > to RSMU misc driver and i2c/spi bus accesses to RSMU MFD driver. I still do not understand why this has to be a kernel driver, sorry. What exactly forces it to be that way? thanks, greg k-h