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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 CA4CFC433E0 for ; Thu, 25 Mar 2021 15:24:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FF4461A2B for ; Thu, 25 Mar 2021 15:24:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231218AbhCYPX5 (ORCPT ); Thu, 25 Mar 2021 11:23:57 -0400 Received: from mga03.intel.com ([134.134.136.65]:14725 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231441AbhCYPXe (ORCPT ); Thu, 25 Mar 2021 11:23:34 -0400 IronPort-SDR: nLuTA4Q48M5v4Wrw+diwdw0P0j5K9vjQSp7O0HBSThBl7AN53mMviyjEt9ja9zSk+qUXsppVn4 8tcuWuDR5z1g== X-IronPort-AV: E=McAfee;i="6000,8403,9934"; a="190982625" X-IronPort-AV: E=Sophos;i="5.81,277,1610438400"; d="scan'208";a="190982625" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2021 08:23:32 -0700 IronPort-SDR: 1KKFaS7stE79Gw49FzsF2skSROJMQmjDMd8dYTej+kYEI4s9FEVrMQS58C+B7pgJffiv3ZrGo/ EOCVjJwVT8yw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,277,1610438400"; d="scan'208";a="514678197" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 25 Mar 2021 08:23:29 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Thu, 25 Mar 2021 17:23:28 +0200 Date: Thu, 25 Mar 2021 17:23:28 +0200 From: Heikki Krogerus To: Alan Stern Cc: Greg Kroah-Hartman , Benson Leung , Prashant Malani , Guenter Roeck , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] usb: Iterator for ports Message-ID: References: <20210325122926.58392-1-heikki.krogerus@linux.intel.com> <20210325122926.58392-2-heikki.krogerus@linux.intel.com> <20210325144109.GB785961@rowland.harvard.edu> 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, Mar 25, 2021 at 05:14:45PM +0200, Heikki Krogerus wrote: > On Thu, Mar 25, 2021 at 10:41:09AM -0400, Alan Stern wrote: > > On Thu, Mar 25, 2021 at 03:29:21PM +0300, Heikki Krogerus wrote: > > > Introducing usb_for_each_port(). It works the same way as > > > usb_for_each_dev(), but instead of going through every USB > > > device in the system, it walks through the USB ports in the > > > system. > > > > > > Signed-off-by: Heikki Krogerus > > > > This has a couple of nasty errors. > > > > > --- > > > drivers/usb/core/usb.c | 43 ++++++++++++++++++++++++++++++++++++++++++ > > > include/linux/usb.h | 1 + > > > 2 files changed, 44 insertions(+) > > > > > > diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c > > > index 2ce3667ec6fae..6d49db9a1b208 100644 > > > --- a/drivers/usb/core/usb.c > > > +++ b/drivers/usb/core/usb.c > > > @@ -398,6 +398,49 @@ int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) > > > } > > > EXPORT_SYMBOL_GPL(usb_for_each_dev); > > > > > > +struct each_hub_arg { > > > + void *data; > > > + int (*fn)(struct device *, void *); > > > +}; > > > + > > > +static int __each_hub(struct device *dev, void *data) > > > +{ > > > + struct each_hub_arg *arg = (struct each_hub_arg *)data; > > > + struct usb_device *hdev = to_usb_device(dev); > > > > to_usb_device() won't work properly if the struct device isn't embedded > > in an actual usb_device structure. And that will happen, since the USB > > bus type holds usb_interface structures as well as usb_devices. > > OK, so I need to filter them out. > > > In fact, you should use usb_for_each_dev here; it already does what you > > want. > > Unfortunately I can't use usb_for_each_dev here, because it deals with > struct usb_device while I need to deal with struct device in the > callback. Ah, I can use it instead of bus_for_each_dev() in usb_for_each_port(). I'll fix these in v2. For the lock I guess I can just use the peer lock (usb_port_peer_mutex)? thanks, -- heikki