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: [1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller() From: Felipe Balbi Message-Id: <87y3eydrs1.fsf@linux.intel.com> Date: Fri, 29 Jun 2018 09:35:10 +0300 To: Robert Jarzmik , Jia-Ju Bai Cc: gregkh@linuxfoundation.org, nicolas.ferre@microchip.com, keescook@chromium.org, allen.lkml@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: SGksCgpSb2JlcnQgSmFyem1payA8cm9iZXJ0LmphcnptaWtAZnJlZS5mcj4gd3JpdGVzOgoKPiBK aWEtSnUgQmFpIDxiYWlqaWFqdTE5OTBAZ21haWwuY29tPiB3cml0ZXM6Cj4KPj4gVGhlIGRyaXZl ciBtYXkgc2xlZXAgd2l0aCBob2xkaW5nIGEgc3BpbmxvY2suCj4+IFRoZSBmdW5jdGlvbiBjYWxs IHBhdGhzIChmcm9tIGJvdHRvbSB0byB0b3ApIGluIExpbnV4LTQuMTYuNyBhcmU6Cj4+Cj4+IFtG VU5DXSBtc2xlZXAKPj4gZHJpdmVycy91c2IvZ2FkZ2V0L3VkYy9yOGE2NjU5Ny11ZGMuYywgODM5 OiAKPj4gCQltc2xlZXAgaW4gaW5pdF9jb250cm9sbGVyCj4+IGRyaXZlcnMvdXNiL2dhZGdldC91 ZGMvcjhhNjY1OTctdWRjLmMsIDk2OiAKPj4gCQlpbml0X2NvbnRyb2xsZXIgaW4gcjhhNjY1OTdf dXNiX2Rpc2Nvbm5lY3QKPj4gZHJpdmVycy91c2IvZ2FkZ2V0L3VkYy9yOGE2NjU5Ny11ZGMuYywg OTM6IAo+PiAJCXNwaW5fbG9jayBpbiByOGE2NjU5N191c2JfZGlzY29ubmVjdAo+Cj4gVGhhdCBz aG91bGQgbm90IGhhcHBlbi4uLgo+Cj4gSWYgdGhpbmsgdGhlIGlzc3VlIHlvdSBoYXZlIGlzIHRo YXQgeW91ciB1c2JfY29ubmVjdCgpIGFuZCB1c2JfZGlzY29ubmVjdCgpIGFyZQo+IGNhbGxlZCBm cm9tIGludGVycnVwdCBjb250ZXh0LiBJIHRoaW5rIHRoZSBwcm9wZXIgZml4LCBhcyB3aGF0IGlz IGRvbmUgaW4gbW9zdAo+IHVkYyBwaHlzLCBpcyB0byBzY2hlZHVsZSBhIHdvcmtxdWV1ZSwgc2Vl IGRyaXZlcnMvdXNiL3BoeS9waHktZ3Bpby12YnVzLXVzYi5jLAo+IGdwaW9fdmJ1c19kYXRhLnZi dXMuCgphcmdoLCBuby4gTm8gd29ya3F1ZXVlcyBuZWVkZWQgaGVyZS4gU29ycnkK 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=-1.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 7B74EC43141 for ; Fri, 29 Jun 2018 06:38:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F98A27AE1 for ; Fri, 29 Jun 2018 06:38:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F98A27AE1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933512AbeF2Gh7 (ORCPT ); Fri, 29 Jun 2018 02:37:59 -0400 Received: from mga18.intel.com ([134.134.136.126]:31639 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932209AbeF2Gh6 (ORCPT ); Fri, 29 Jun 2018 02:37:58 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jun 2018 23:37:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,285,1526367600"; d="scan'208";a="63107232" Received: from pipin.fi.intel.com (HELO localhost) ([10.237.68.37]) by orsmga003.jf.intel.com with ESMTP; 28 Jun 2018 23:37:44 -0700 From: Felipe Balbi To: Robert Jarzmik , Jia-Ju Bai Cc: gregkh@linuxfoundation.org, nicolas.ferre@microchip.com, keescook@chromium.org, allen.lkml@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller() In-Reply-To: <87efh0o6f9.fsf@belgarion.home> References: <20180620035453.7721-1-baijiaju1990@gmail.com> <87efh0o6f9.fsf@belgarion.home> Date: Fri, 29 Jun 2018 09:35:10 +0300 Message-ID: <87y3eydrs1.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Robert Jarzmik writes: > Jia-Ju Bai writes: > >> The driver may sleep with holding a spinlock. >> The function call paths (from bottom to top) in Linux-4.16.7 are: >> >> [FUNC] msleep >> drivers/usb/gadget/udc/r8a66597-udc.c, 839: >> msleep in init_controller >> drivers/usb/gadget/udc/r8a66597-udc.c, 96: >> init_controller in r8a66597_usb_disconnect >> drivers/usb/gadget/udc/r8a66597-udc.c, 93: >> spin_lock in r8a66597_usb_disconnect > > That should not happen... > > If think the issue you have is that your usb_connect() and usb_disconnect() are > called from interrupt context. I think the proper fix, as what is done in most > udc phys, is to schedule a workqueue, see drivers/usb/phy/phy-gpio-vbus-usb.c, > gpio_vbus_data.vbus. argh, no. No workqueues needed here. Sorry -- balbi