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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 C5A1BC76188 for ; Mon, 22 Jul 2019 11:48:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90F322184E for ; Mon, 22 Jul 2019 11:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563796127; bh=eykSHfnl91fm/zvBMeCc8yWb/8vQuZ0jAGDMw66izu0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=yjub32cLim592PXvkZWjNotf0aJLKX93EKwOqhwDG+s7ghVuWlnn1wOf7NxjKcgW+ yFliEYtrhhXHv6uKARxMSjH2WljUUvtYQRZsKwEezQcNWGhIewZgkMEiVhchJej+81 mrzWczDgix/JlQ/3MjIKAkUFp2kO3/Yt9tyw/8Sw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729887AbfGVLso (ORCPT ); Mon, 22 Jul 2019 07:48:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:48334 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728929AbfGVLsn (ORCPT ); Mon, 22 Jul 2019 07:48:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 75ACC2184E; Mon, 22 Jul 2019 11:48:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563796122; bh=eykSHfnl91fm/zvBMeCc8yWb/8vQuZ0jAGDMw66izu0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uv5zT+EqBSp94cqvlDWja0OoZzX7VHMHStJ55fF9xDfUyJp5wkjCZHVt/lkYa8gbp 1jLNgfCbnnVlmS+Lgzptnb6354tj0wiH6Vj+PazxHCANwZ9C0Oq1O6yRJQiGiUAIjC e4As2VJxRuv8exrTj/unnYx3ytDLRzU6kR/8yiKE= Date: Mon, 22 Jul 2019 13:48:39 +0200 From: "gregkh@linuxfoundation.org" To: Pawel Laszczak Cc: Pavel Machek , "felipe.balbi@linux.intel.com" , "linux-usb@vger.kernel.org" , "rogerq@ti.com" , "linux-kernel@vger.kernel.org" , "jbergsagel@ti.com" , "nsekhar@ti.com" , "nm@ti.com" , Suresh Punnoose , Jayshri Dajiram Pawar , Rahul Kumar , Anil Joy Varughese Subject: Re: [PATCH v10 0/6] Introduced new Cadence USBSS DRD Driver. Message-ID: <20190722114839.GA10515@kroah.com> References: <1563733939-21214-1-git-send-email-pawell@cadence.com> <20190721190335.GA19831@xo-6d-61-c0.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Jul 22, 2019 at 09:58:42AM +0000, Pawel Laszczak wrote: > Hi, > > > > >> This patch introduce new Cadence USBSS DRD driver to linux kernel. > >> > >> The Cadence USBSS DRD Controller is a highly configurable IP Core which > >> can be instantiated as Dual-Role Device (DRD), Peripheral Only and > >> Host Only (XHCI)configurations. > > > >I see you are using debugfs to select between DRD, peripheral-onlyh and XHCI... > > > >Is that good idea? > > Yes driver allows selecting dr_mode by debugfs. Controller also support such functionality > so I don't understand why would it not be a good idea. > > I personally use this for testing but it can be used to limit controller functionality without > recompiling kernel. debugfs is ONLY for debugging, never rely on it being enabled, or mounted, on a system in order to have any normal operation happen. So for testing, yes, this is fine. If this is going to be the normal api/interface for how to control this driver, no, that is not acceptable at all. thanks, greg k-h