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=-3.8 required=3.0 tests=BAYES_00, 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 BD566C433E6 for ; Tue, 16 Feb 2021 13:37:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8161164E08 for ; Tue, 16 Feb 2021 13:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbhBPNhg (ORCPT ); Tue, 16 Feb 2021 08:37:36 -0500 Received: from mx2.suse.de ([195.135.220.15]:42078 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230077AbhBPNhd (ORCPT ); Tue, 16 Feb 2021 08:37:33 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 00B30AC69; Tue, 16 Feb 2021 13:36:50 +0000 (UTC) Message-ID: <5164bb01b7f3cf71926109a37b9e3957cfb630ba.camel@suse.de> Subject: Re: [PATCH v5 3/3] drm: Add Generic USB Display driver From: Oliver Neukum To: Noralf =?ISO-8859-1?Q?Tr=F8nnes?= , dri-devel@lists.freedesktop.org Cc: linux-usb@vger.kernel.org, sam@ravnborg.org, peter@stuge.se, lkundrak@v3.sk, markus@raatikainen.cc, pontus.fuchs@gmail.com, hudson@trmm.net, th020394@gmail.com, Daniel Vetter Date: Tue, 16 Feb 2021 14:36:37 +0100 In-Reply-To: <20210212174609.58977-4-noralf@tronnes.org> References: <20210212174609.58977-1-noralf@tronnes.org> <20210212174609.58977-4-noralf@tronnes.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Am Freitag, den 12.02.2021, 18:46 +0100 schrieb Noralf Trønnes: > +static void gud_connector_early_unregister(struct drm_connector *connector) > +{ > + struct gud_connector *gconn = to_gud_connector(connector); > + > + backlight_device_unregister(gconn->backlight); > + cancel_work_sync(&gconn->backlight_work); > +} Hi, this looks like you are creating a race condition where the queued work may operate on an already unregistered backlight. Regards Oliver