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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CAC0C32771 for ; Sat, 24 Sep 2022 06:56:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233173AbiIXG4d (ORCPT ); Sat, 24 Sep 2022 02:56:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233353AbiIXG43 (ORCPT ); Sat, 24 Sep 2022 02:56:29 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D0FB1C915; Fri, 23 Sep 2022 23:56:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1A6AC60B5B; Sat, 24 Sep 2022 06:56:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E87EC433C1; Sat, 24 Sep 2022 06:56:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664002587; bh=BSAa+I4RIdZWGzshe6klmFRiSF/Qy5u0G3INxPjE03s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RPA1JcMfo1TKe/PFlRooU2HR/7jYkduwKByfrkCrKpay2GR6NJzYjFL9uBcvYlBzy XKht7TJIZZH9HjQWFtohzuL1GaF/MkdGnMOqJD/xveeztbAD+RFVBHwEH89TtcQ7o8 eUFkz+CRiKLWXbj5jIbeh8EwCuYfdqYelYFu+qtE= Date: Sat, 24 Sep 2022 08:56:58 +0200 From: Greg Kroah-Hartman To: Jeff Harris Cc: Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: serial: New xr20m117x driver questions Message-ID: References: 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 Fri, Sep 23, 2022 at 11:29:52AM -0400, Jeff Harris wrote: > I have a driver for the MaxLinear XR20M117x family of UARTs that I'd like > to contribute but have a couple questions. The driver is heavily based on > the existing sc16is7xx driver. The driver started with the sample driver > from MaxLinear for Linux 3.x.x, but as the integration of their driver > proceeded into our 4.4 kernel, there were features and fixes missing that > were present in the current sc16is7xx driver. > > The register set is similar, but there are a few places where the behavior > is different. Would it be best to create a new driver or add the XR20M117x > UARTs to the sc16is7xx driver with a flag to choose one behavior or the > other? Probably a flag, but let's see the patch to be sure. > I have developed and tested the driver as a back-port of the mainline > sc16is7xx driver to the 4.4 kernel used on our embedded platform. I don't > have a ready method to test the driver with a newer kernel (other than > ensuring compilation success). Is that a concern for accepting the driver? Please don't use any new devices with the obsolete and insecure and out-of-date 4.4 kernel tree, that's going to be a regulatory nightmare when you realize how broken it is. Anyway, it has to work in the latest kernel tree for us to be able to accept it as we can't go back in time and do new development on old kernels :) thanks, greg k-h