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 D5376C433E0 for ; Thu, 25 Feb 2021 10:51:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9259164E21 for ; Thu, 25 Feb 2021 10:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234952AbhBYKv2 (ORCPT ); Thu, 25 Feb 2021 05:51:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:40788 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234037AbhBYKjX (ORCPT ); Thu, 25 Feb 2021 05:39:23 -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 2AB1FAAAE; Thu, 25 Feb 2021 10:38:36 +0000 (UTC) Date: Thu, 25 Feb 2021 11:38:35 +0100 Message-ID: From: Takashi Iwai To: Anton Yakovlev Cc: , , , "Michael S. Tsirkin" , Jaroslav Kysela , Takashi Iwai , Jason Wang , Subject: Re: [PATCH v5 2/9] ALSA: virtio: add virtio sound driver In-Reply-To: <20210222153444.348390-3-anton.yakovlev@opensynergy.com> References: <20210222153444.348390-1-anton.yakovlev@opensynergy.com> <20210222153444.348390-3-anton.yakovlev@opensynergy.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 22 Feb 2021 16:34:37 +0100, Anton Yakovlev wrote: > +static int virtsnd_find_vqs(struct virtio_snd *snd) > +{ > + struct virtio_device *vdev = snd->vdev; > + vq_callback_t *callbacks[VIRTIO_SND_VQ_MAX] = { > + [VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb > + }; > + const char *names[VIRTIO_SND_VQ_MAX] = { Shouldn't be static? Also it's often const char * const names[] = { ... } unless you overwrite something. > +/** > + * virtsnd_reset_fn() - Kernel worker's function to reset the device. > + * @work: Reset device work. > + * > + * Context: Process context. > + */ > +static void virtsnd_reset_fn(struct work_struct *work) > +{ > + struct virtio_snd *snd = > + container_of(work, struct virtio_snd, reset_work); > + struct virtio_device *vdev = snd->vdev; > + struct device *dev = &vdev->dev; > + int rc; > + > + dev_info(dev, "sound device needs reset\n"); > + > + /* > + * It seems that the only way to properly reset the device is to remove > + * and re-create the ALSA sound card device. > + */ > + rc = device_reprobe(dev); > + if (rc) > + dev_err(dev, "failed to reprobe sound device: %d\n", rc); Now I'm wondering whether it's safe to do that from this place. Basically device_reprobe() unbinds the device that releases the full resources once including the devm_* stuff. And this work itself is in a part of devm allocated resource, so it'll be released there. That said, we might hit use-after-free... This needs to be verified. thanks, Takashi