From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: usb/hcd: Send a uevent signaling that the host controller has died From: Oliver Neukum Message-Id: <1554964555.21725.14.camel@suse.com> Date: Thu, 11 Apr 2019 08:35:55 +0200 To: Raul E Rangel , linux-usb@vger.kernel.org Cc: Miquel Raynal , djkurtz@chromium.org, Dmitry Torokhov , groeck@chromium.org, "Gustavo A. R. Silva" , Martin Blumenstingl , Johan Hovold , Sebastian Andrzej Siewior , Mathias Nyman , Greg Kroah-Hartman , Alan Stern , Roger Quadros , linux-kernel@vger.kernel.org List-ID: T24gTWksIDIwMTktMDQtMTAgYXQgMTQ6MzUgLTA2MDAsIFJhdWwgRSBSYW5nZWwgd3JvdGU6Cj4g VGhpcyBjaGFuZ2Ugd2lsbCBzZW5kIGEgQ0hBTkdFIGV2ZW50IHRvIHVkZXYgd2l0aCB0aGUgREVB RCBlbnZpcm9ubWVudAo+IHZhcmlhYmxlIHNldCB3aGVuIHRoZSBIQyBkaWVzLiBJIGNob3NlIHRo aXMgaW5zdGVhZCBvZiBhbnkgb2YgdGhlIG90aGVyCj4gdWRldiBldmVudHMgYmVjYXVzZSBpdCdz IHJlcHJlc2VudGluZyBhIHN0YXRlIGNoYW5nZSBpbiB0aGUgaG9zdAo+IGNvbnRyb2xsZXIuIFRo ZSBvbmx5IG90aGVyIGV2ZW50IHRoYXQgbWlnaHQgaGF2ZSBmaXQgd2FzIE9GRkxJTkUsIGJ1dAo+ IHRoYXQgc2VlbXMgdG8gYmUgdXNlZCBmb3IgaG90LXJlbW92YWwuCj4gCj4gQnkgbm90aWZ5aW5n IHVzZXIgc3BhY2UgdGhlIGFwcHJvcHJpYXRlIHBvbGljaWVzIGNhbiBiZSBhcHBsaWVkLgo+IGUu Zy4sCj4gICogQ29sbGVjdCBlcnJvciBsb2dzLgo+ICAqIE5vdGlmeSB0aGUgdXNlciB0aGF0IFVT QiBpcyBubyBsb25nZXIgZnVuY3Rpb25hbC4KPiAgKiBQZXJmb3JtIGEgZ3JhY2VmdWwgcmVib290 LgoKQ291bGQgeW91IHBsZWFzZSBtYWtlIHN1cmUgdGhpcyB0eXBlIG9mIGV2ZW50IGlzIHNoYXJl ZCB3aXRoIG90aGVyCnN1YnN5c3RlbXMgd2hvc2UgZGV2aWNlcyBjYW4gImRpZSI/Ckl0IGxvb2tz IHRvIG1lIGxpa2UgU0NTSSBvZmZsaW5lIHNob3VsZCBmb3IgZXhhbXBsZSBjcmVhdGUgdGhlCnNh bWUgZXZlbnQuIFRoaXMga2luZCBvZiB0aGluZyBuZWVkcyB0byBiZSBkb2N1bWVudGVkLgoKCVJl Z2FyZHMKCQlPbGl2ZXIK 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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 218BAC10F13 for ; Thu, 11 Apr 2019 08:28:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF3E22083E for ; Thu, 11 Apr 2019 08:28:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726830AbfDKI2F (ORCPT ); Thu, 11 Apr 2019 04:28:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:59068 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726121AbfDKI2F (ORCPT ); Thu, 11 Apr 2019 04:28:05 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id BF575AC69; Thu, 11 Apr 2019 08:28:03 +0000 (UTC) Message-ID: <1554964555.21725.14.camel@suse.com> Subject: Re: [PATCH] usb/hcd: Send a uevent signaling that the host controller has died From: Oliver Neukum To: Raul E Rangel , linux-usb@vger.kernel.org Cc: Miquel Raynal , djkurtz@chromium.org, Dmitry Torokhov , groeck@chromium.org, "Gustavo A. R. Silva" , Martin Blumenstingl , Johan Hovold , Sebastian Andrzej Siewior , Mathias Nyman , Greg Kroah-Hartman , Alan Stern , Roger Quadros , linux-kernel@vger.kernel.org In-Reply-To: <20190410203520.248158-1-rrangel@chromium.org> References: <20190410203520.248158-1-rrangel@chromium.org> Content-Type: text/plain; charset="UTF-8" Date: Thu, 11 Apr 2019 08:35:55 +0200 Mime-Version: 1.0 X-Mailer: Evolution 3.26.6 Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Message-ID: <20190411063555.p8eh52OeLuZGL4xriRNmdjv8R6UV4ziafMHM08YT5EY@z> On Mi, 2019-04-10 at 14:35 -0600, Raul E Rangel wrote: > This change will send a CHANGE event to udev with the DEAD environment > variable set when the HC dies. I chose this instead of any of the other > udev events because it's representing a state change in the host > controller. The only other event that might have fit was OFFLINE, but > that seems to be used for hot-removal. > > By notifying user space the appropriate policies can be applied. > e.g., > * Collect error logs. > * Notify the user that USB is no longer functional. > * Perform a graceful reboot. Could you please make sure this type of event is shared with other subsystems whose devices can "die"? It looks to me like SCSI offline should for example create the same event. This kind of thing needs to be documented. Regards Oliver