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 4F0A4C433DB for ; Mon, 1 Feb 2021 14:26:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1362964DD9 for ; Mon, 1 Feb 2021 14:26:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229680AbhBAO0o (ORCPT ); Mon, 1 Feb 2021 09:26:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:57000 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbhBAO0g (ORCPT ); Mon, 1 Feb 2021 09:26:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7143964DDE; Mon, 1 Feb 2021 14:25:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612189555; bh=QQqIk1jrL834oNJT0Ge0l4qRW+ufXIGBw4d9FnRSEdc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vQ9Ktf9+0vr8htx8QoqqdorkeVexnx5/TLccE9me/oeOkQK9BeIZ9EP0wJ2O+6RQm G9FJCrm/hB5+XDmipgt6eNSJ28iQyfUQ6+5DapHI208X7RxkvHwVIGo3WEftzWwk2v UPd2n6Vx4URUxkdDLsgOLK2YqWI3SEFK6FbAq4Vo= Date: Mon, 1 Feb 2021 15:25:53 +0100 From: Greg KH To: eli.billauer@gmail.com Cc: arnd@arndb.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] char: xillybus: Add driver for XillyUSB (Xillybus variant for USB) Message-ID: References: <20210201141651.62853-1-eli.billauer@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210201141651.62853-1-eli.billauer@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 01, 2021 at 04:16:51PM +0200, eli.billauer@gmail.com wrote: > From: Eli Billauer > > The XillyUSB driver is the USB variant for the Xillybus FPGA IP core. > Even though it presents a nearly identical API on the FPGA and host, > it's almost a complete rewrite of the driver: The framework for exchanging > data on a USB bus is fundamentally different from doing the same with a > PCIe interface, which leaves very little in common between the existing > driver and the new one for XillyUSB. As this has nothing to do with the existing XillyBus code, and you aren't doing anything "fancy" with the character device nodes, why does this need to be a kernel driver at all? Why can't you just use libusb and talk to the device directly from userspace with no kernel driver needed? And always cc: linux-usb@vger.kernel.org when submitting a USB driver so that the developers there can review it. thanks, greg k-h