From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fg-out-1718.google.com ([72.14.220.158]:10891 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754285Ab0D3VFz (ORCPT ); Fri, 30 Apr 2010 17:05:55 -0400 Received: by fg-out-1718.google.com with SMTP id 19so73268fgg.1 for ; Fri, 30 Apr 2010 14:05:54 -0700 (PDT) From: Christian Lamparter To: linux-wireless@vger.kernel.org Subject: [PATCH] ar9170: wait for asynchronous firmware loading Date: Thu, 29 Apr 2010 17:53:33 +0200 Cc: Johannes Berg , linville@tuxdriver.com MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201004291753.33414.chunkeey@googlemail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: This patch fixes a regression introduced by the following patch: "ar9170: load firmware asynchronously" When we kick off a firmware loading request and then unbind, or disconnect the usb device right away, we get into trouble: > ------------[ cut here ]------------ > WARNING: at lib/kref.c:44 kref_get+0x1c/0x20() > Hardware name: 18666GU > Modules linked in: ar9170usb [...] > Pid: 6588, comm: firmware/ar9170 Not tainted 2.6.34-rc5-wl #43 > Call Trace: > [] ? warn_slowpath_common+0x6e/0xb0 > [] ? kref_get+0x1c/0x20 > [] ? warn_slowpath_null+0x13/0x20 > [] ? kref_get+0x1c/0x20 > [] ? kobject_get+0xf/0x20 > [] ? get_device+0x10/0x20 > [] ? device_add+0x60/0x530 > [] ? kobject_init+0x25/0xa0 > [] ? _request_firmware+0x139/0x3e0 > [] ? request_firmware_work_func+0x20/0x70 > [] ? request_firmware_work_func+0x0/0x70 > [] ? kthread+0x74/0x80 > [] ? kthread+0x0/0x80 > [] ? kernel_thread_helper+0x6/0x10 >---[ end trace 2d50bd818f64a1b7 ]--- - followed by a random Oops - Avoid that by waiting for the firmware loading to finish (whether successfully or not) before the unbind in ar9170_usb_disconnect. Reported-by: Johannes Berg Bug-fixed-by: Johannes Berg Signed-off-by: Christian Lamparter --- diff --git a/drivers/net/wireless/ath/ar9170/usb.c b/drivers/net/wireless/ath/ar9170/usb.c index c1c7c42..7bae7fd 100644 --- a/drivers/net/wireless/ath/ar9170/usb.c +++ b/drivers/net/wireless/ath/ar9170/usb.c @@ -737,12 +737,16 @@ static void ar9170_usb_firmware_failed(struct ar9170_usb *aru) { struct device *parent = aru->udev->dev.parent; + complete(&aru->firmware_loading_complete); + /* unbind anything failed */ if (parent) down(&parent->sem); device_release_driver(&aru->udev->dev); if (parent) up(&parent->sem); + + usb_put_dev(aru->udev); } static void ar9170_usb_firmware_finish(const struct firmware *fw, void *context) @@ -771,6 +775,8 @@ static void ar9170_usb_firmware_finish(const struct firmware *fw, void *context) if (err) goto err_unrx; + complete(&aru->firmware_loading_complete); + usb_put_dev(aru->udev); return; err_unrx: @@ -868,6 +874,7 @@ static int ar9170_usb_probe(struct usb_interface *intf, init_usb_anchor(&aru->tx_pending); init_usb_anchor(&aru->tx_submitted); init_completion(&aru->cmd_wait); + init_completion(&aru->firmware_loading_complete); spin_lock_init(&aru->tx_urb_lock); aru->tx_pending_urbs = 0; @@ -887,6 +894,7 @@ static int ar9170_usb_probe(struct usb_interface *intf, if (err) goto err_freehw; + usb_get_dev(aru->udev); return request_firmware_nowait(THIS_MODULE, 1, "ar9170.fw", &aru->udev->dev, GFP_KERNEL, aru, ar9170_usb_firmware_step2); @@ -906,6 +914,9 @@ static void ar9170_usb_disconnect(struct usb_interface *intf) return; aru->common.state = AR9170_IDLE; + + wait_for_completion(&aru->firmware_loading_complete); + ar9170_unregister(&aru->common); ar9170_usb_cancel_urbs(aru); diff --git a/drivers/net/wireless/ath/ar9170/usb.h b/drivers/net/wireless/ath/ar9170/usb.h index a2ce3b1..919b060 100644 --- a/drivers/net/wireless/ath/ar9170/usb.h +++ b/drivers/net/wireless/ath/ar9170/usb.h @@ -71,6 +71,7 @@ struct ar9170_usb { unsigned int tx_pending_urbs; struct completion cmd_wait; + struct completion firmware_loading_complete; int readlen; u8 *readbuf;