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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 10533C43467 for ; Wed, 14 Oct 2020 16:27:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B8C092222E for ; Wed, 14 Oct 2020 16:27:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388416AbgJNQ1Z (ORCPT ); Wed, 14 Oct 2020 12:27:25 -0400 Received: from netrider.rowland.org ([192.131.102.5]:58325 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S2388364AbgJNQ1W (ORCPT ); Wed, 14 Oct 2020 12:27:22 -0400 Received: (qmail 719448 invoked by uid 1000); 14 Oct 2020 12:27:21 -0400 Date: Wed, 14 Oct 2020 12:27:21 -0400 From: Alan Stern To: Thomas Gleixner Cc: LKML , Peter Zijlstra , "Ahmed S. Darwish" , Sebastian Andrzej Siewior , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Thomas Winischhofer , Johan Hovold , Mathias Nyman , Valentina Manea , Shuah Khan , linux-omap@vger.kernel.org, Kukjin Kim , Krzysztof Kozlowski , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Felipe Balbi , Duncan Sands Subject: Re: [patch 11/12] usb: core: Replace in_interrupt() in comments Message-ID: <20201014162721.GE712494@rowland.harvard.edu> References: <20201014145215.518912759@linutronix.de> <20201014145728.318078828@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201014145728.318078828@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Oct 14, 2020 at 04:52:26PM +0200, Thomas Gleixner wrote: > From: Ahmed S. Darwish > > The usage of in_interrupt() in drivers is phased out for various reasons. > > Various comments use !in_interrupt() to describe calling context for > functions which might sleep. That's wrong because the calling context has > to be preemptible task context, which is not what !in_interrupt() > describes. > > Replace !in_interrupt() with more accurate plain text descriptions. > > The comment for usb_hcd_poll_rh_status() is misleading as this function is > called from all kinds of contexts including preemptible task > context. Remove it as there is obviously no restriction. > > Signed-off-by: Ahmed S. Darwish > Signed-off-by: Sebastian Andrzej Siewior > Signed-off-by: Thomas Gleixner > Cc: Greg Kroah-Hartman > Cc: linux-usb@vger.kernel.org > > --- > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -746,9 +746,6 @@ static int rh_call_control (struct usb_h > * Root Hub interrupt transfers are polled using a timer if the > * driver requests it; otherwise the driver is responsible for > * calling usb_hcd_poll_rh_status() when an event occurs. > - * > - * Completions are called in_interrupt(), but they may or may not > - * be in_irq(). This comment should not be removed; instead it should be changed to say that completion handlers are called with interrupts disabled. > @@ -1691,7 +1690,6 @@ static void usb_giveback_urb_bh(unsigned > * @hcd: host controller returning the URB > * @urb: urb being returned to the USB device driver. > * @status: completion status code for the URB. > - * Context: in_interrupt() The comment should be changed to say that the routine runs in a BH handler (or however you want to express it). > --- a/drivers/usb/core/message.c > +++ b/drivers/usb/core/message.c > @@ -934,7 +939,7 @@ int usb_get_device_descriptor(struct usb > /* > * usb_set_isoch_delay - informs the device of the packet transmit delay > * @dev: the device whose delay is to be informed > - * Context: !in_interrupt() > + * Context: can sleep Why is this comment different from all the others? Alan Stern