From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= Subject: Re: usb_wwan_write() called while device still being resumed Date: Thu, 14 Feb 2013 18:41:27 +0100 Message-ID: <87ehgivlmg.fsf@nemi.mork.no> References: <511CBCE8.9070204@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <511CBCE8.9070204@nvidia.com> (Alex Courbot's message of "Thu, 14 Feb 2013 19:31:04 +0900") Sender: linux-kernel-owner@vger.kernel.org To: Alex Courbot Cc: USB list , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Alexandre Courbot List-Id: linux-pm@vger.kernel.org Alex Courbot writes: > The board features a USB GSM modem using the usb_wwan module. Once in > a while, when the system resumes from LP0, a NET_RX softirq will be > triggered while the modem is still being resumed, calling > usb_wwan_write(). This will cause usb_autopm_get_interface_async() > inside usb_wwan_write() to fail because the runtime PM disable_depth > is still equal to 1 since device_resume() has not completed yet. As a > result, the modem just stops working. I believe the usb_autopm_get_interface_async() failing is OK in this case, but that should not cause the modem to stop working. Wonder if this patch solves the problem? : =46rom: =3D?UTF-8?q?Bj=3DC3=3DB8rn=3D20Mork?=3D Date: Thu, 14 Feb 2013 18:34:48 +0100 Subject: [PATCH] USB: usb_wwan: clear port busy state on error MIME-Version: 1.0 Content-Type: text/plain; charset=3DUTF-8 Content-Transfer-Encoding: 8bit Reported-by: Alex Courbot Signed-off-by: Bj=C3=B8rn Mork --- drivers/usb/serial/usb_wwan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwa= n.c index 01c94aa..44e106d 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -230,8 +230,10 @@ int usb_wwan_write(struct tty_struct *tty, struct = usb_serial_port *port, usb_pipeendpoint(this_urb->pipe), i); =20 err =3D usb_autopm_get_interface_async(port->serial->interface); - if (err < 0) + if (err < 0) { + clear_bit(i, &portdata->out_busy); break; + } =20 /* send the data */ memcpy(this_urb->transfer_buffer, buf, todo); --=20 1.7.10.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965197Ab3BNRlu (ORCPT ); Thu, 14 Feb 2013 12:41:50 -0500 Received: from canardo.mork.no ([148.122.252.1]:41490 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934487Ab3BNRlk convert rfc822-to-8bit (ORCPT ); Thu, 14 Feb 2013 12:41:40 -0500 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= To: Alex Courbot Cc: USB list , "linux-pm\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , Alexandre Courbot Subject: Re: usb_wwan_write() called while device still being resumed Organization: m References: <511CBCE8.9070204@nvidia.com> Date: Thu, 14 Feb 2013 18:41:27 +0100 In-Reply-To: <511CBCE8.9070204@nvidia.com> (Alex Courbot's message of "Thu, 14 Feb 2013 19:31:04 +0900") Message-ID: <87ehgivlmg.fsf@nemi.mork.no> User-Agent: Gnus/5.11002 (No Gnus v0.20) Emacs/23.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alex Courbot writes: > The board features a USB GSM modem using the usb_wwan module. Once in > a while, when the system resumes from LP0, a NET_RX softirq will be > triggered while the modem is still being resumed, calling > usb_wwan_write(). This will cause usb_autopm_get_interface_async() > inside usb_wwan_write() to fail because the runtime PM disable_depth > is still equal to 1 since device_resume() has not completed yet. As a > result, the modem just stops working. I believe the usb_autopm_get_interface_async() failing is OK in this case, but that should not cause the modem to stop working. Wonder if this patch solves the problem? : From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= Date: Thu, 14 Feb 2013 18:34:48 +0100 Subject: [PATCH] USB: usb_wwan: clear port busy state on error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Reported-by: Alex Courbot Signed-off-by: Bjørn Mork --- drivers/usb/serial/usb_wwan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c index 01c94aa..44e106d 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -230,8 +230,10 @@ int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port, usb_pipeendpoint(this_urb->pipe), i); err = usb_autopm_get_interface_async(port->serial->interface); - if (err < 0) + if (err < 0) { + clear_bit(i, &portdata->out_busy); break; + } /* send the data */ memcpy(this_urb->transfer_buffer, buf, todo); -- 1.7.10.4