From patchwork Wed Jan 18 04:40:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Youn X-Patchwork-Id: 91729 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp845242qgi; Tue, 17 Jan 2017 20:58:17 -0800 (PST) X-Received: by 10.84.209.204 with SMTP id y70mr2212097plh.180.1484715497384; Tue, 17 Jan 2017 20:58:17 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g26si27162976plj.254.2017.01.17.20.58.17; Tue, 17 Jan 2017 20:58:17 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-usb-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-usb-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-usb-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751240AbdARE6P (ORCPT + 4 others); Tue, 17 Jan 2017 23:58:15 -0500 Received: from smtprelay.synopsys.com ([198.182.47.9]:44575 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbdARE6P (ORCPT ); Tue, 17 Jan 2017 23:58:15 -0500 Received: from mailhost.synopsys.com (mailhost3.synopsys.com [10.12.238.238]) by smtprelay.synopsys.com (Postfix) with ESMTP id AEABF24E0162; Tue, 17 Jan 2017 20:41:01 -0800 (PST) Received: from mailhost.synopsys.com (localhost [127.0.0.1]) by mailhost.synopsys.com (Postfix) with ESMTP id 7BF1F84C; Tue, 17 Jan 2017 20:41:01 -0800 (PST) Received: from US01WEHTC2.internal.synopsys.com (us01wehtc2-vip.internal.synopsys.com [10.12.239.238]) by mailhost.synopsys.com (Postfix) with ESMTP id 3C7A0838; Tue, 17 Jan 2017 20:41:01 -0800 (PST) Received: from US01WEHTC3.internal.synopsys.com (10.15.84.232) by US01WEHTC2.internal.synopsys.com (10.12.239.237) with Microsoft SMTP Server (TLS) id 14.3.266.1; Tue, 17 Jan 2017 20:41:01 -0800 Received: from starbug (10.13.184.20) by US01WEHTC3.internal.synopsys.com (10.15.84.231) with Microsoft SMTP Server (TLS) id 14.3.266.1; Tue, 17 Jan 2017 20:40:58 -0800 Received: by starbug (sSMTP sendmail emulation); Tue, 17 Jan 2017 20:40:58 -0800 Date: Tue, 17 Jan 2017 20:40:58 -0800 Message-ID: <98ffc61fd3ed13abe7c3befd40e4da670e0eada4.1484704738.git.johnyoun@synopsys.com> In-Reply-To: References: From: John Youn Subject: [PATCH v2 22/28] usb: dwc2: Avoid sleeping while holding hsotg->lock To: John Youn , Felipe Balbi , CC: Vardan Mikayelyan , Rob Herring , Kishon Vijay Abraham I , Amit Pundir , John Stultz , Wei Xu , Guodong Xu , Chen Yu , Stefan Wahren , "Douglas Anderson" MIME-Version: 1.0 X-Originating-IP: [10.13.184.20] Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: John Stultz Basically when plugging in various cables in different orders, I'm occasionally seeing the following BUG splat: [ 86.215403] BUG: scheduling while atomic: kworker/u16:2/53/0x00000002 [ 86.219164] usb 1-1: USB disconnect, device number 9 [ 86.226845] Preemption disabled at:[ 86.230218] [] dwc2_conn_id_status_change+0x120/0x250 [ 86.236894] CPU: 0 PID: 53 Comm: kworker/u16:2 Tainted: G W 4.9.0-rc8-00051-gd5a7979-dirty #1702 [ 86.246836] Hardware name: HiKey Development Board (DT) [ 86.252100] Workqueue: dwc2 dwc2_conn_id_status_change [ 86.257279] Call trace: [ 86.259771] [] dump_backtrace+0x0/0x1a0 [ 86.265210] [] show_stack+0x14/0x20 [ 86.270308] [] dump_stack+0x90/0xb0 [ 86.275401] [] __schedule_bug+0x6c/0xb8 [ 86.280841] [] __schedule+0x4f8/0x5b0 [ 86.286099] [] schedule+0x38/0xa0 [ 86.291017] [] schedule_hrtimeout_range_clock+0x8c/0xf0 [ 86.297846] [] schedule_hrtimeout_range+0x10/0x18 [ 86.304150] [] usleep_range+0x50/0x58 [ 86.309418] [] dwc2_wait_for_mode.isra.4+0x54/0xd0 [ 86.315815] [] dwc2_core_reset+0xe0/0x168 [ 86.321431] [] dwc2_hsotg_core_init_disconnected+0x2c/0x310 [ 86.328602] [] dwc2_conn_id_status_change+0x130/0x250 [ 86.335254] [] process_one_work+0x118/0x370 [ 86.341035] [] worker_thread+0x48/0x498 [ 86.346473] [] kthread+0xd0/0xe8 [ 86.351299] [] ret_from_fork+0x10/0x50 This seems to be caused by the dwc2_wait_for_mode() calling usleep_range() while the hstog->lock spinlock is held, since we take that before calling dwc2_hsotg_core_init_disconnected(). This patch avoids the issue by adding an extra argument to dwc2_core_reset(), as suggested by John Youn, which allows us to skip the waiting, which should be unnecessary when calling from dwc2_hsotg_core_init_disconnected(). Cc: Wei Xu Cc: Guodong Xu Cc: Amit Pundir Cc: Rob Herring Cc: John Youn Cc: Douglas Anderson Cc: Chen Yu Cc: Vardan Mikayelyan Cc: Kishon Vijay Abraham I Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org Signed-off-by: John Stultz Signed-off-by: John Youn --- drivers/usb/dwc2/core.c | 6 +++--- drivers/usb/dwc2/core.h | 2 +- drivers/usb/dwc2/gadget.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c index c987547a1e7b..7195366e26bf 100644 --- a/drivers/usb/dwc2/core.c +++ b/drivers/usb/dwc2/core.c @@ -313,7 +313,7 @@ static bool dwc2_iddig_filter_enabled(struct dwc2_hsotg *hsotg) * Do core a soft reset of the core. Be careful with this because it * resets all the internal state machines of the core. */ -int dwc2_core_reset(struct dwc2_hsotg *hsotg) +int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait) { u32 greset; int count = 0; @@ -369,7 +369,7 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg) } } while (!(greset & GRSTCTL_AHBIDLE)); - if (wait_for_host_mode) + if (wait_for_host_mode && !skip_wait) dwc2_wait_for_mode(hsotg, true); return 0; @@ -500,7 +500,7 @@ int dwc2_core_reset_and_force_dr_mode(struct dwc2_hsotg *hsotg) { int retval; - retval = dwc2_core_reset(hsotg); + retval = dwc2_core_reset(hsotg, false); if (retval) return retval; diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index 2bd3ea624cfc..b07bf7be2034 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -1088,7 +1088,7 @@ static inline bool dwc2_is_hs_iot(struct dwc2_hsotg *hsotg) * The following functions support initialization of the core driver component * and the DWC_otg controller */ -int dwc2_core_reset(struct dwc2_hsotg *hsotg); +int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait); int dwc2_core_reset_and_force_dr_mode(struct dwc2_hsotg *hsotg); int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg); int dwc2_exit_hibernation(struct dwc2_hsotg *hsotg, bool restore); diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index ce5a1fb3a8ef..288402d44fce 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -3161,7 +3161,7 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg, kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET); if (!is_usb_reset) - if (dwc2_core_reset(hsotg)) + if (dwc2_core_reset(hsotg, true)) return; /*