From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759415Ab1KWAlu (ORCPT ); Tue, 22 Nov 2011 19:41:50 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42970 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759388Ab1KWAlq (ORCPT ); Tue, 22 Nov 2011 19:41:46 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Nov 22 16:24:05 2011 Message-Id: <20111123002405.450677495@clark.kroah.org> User-Agent: quilt/0.48-20.1.2 Date: Tue, 22 Nov 2011 16:23:16 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Gertjan van Wingerde , Ivo van Doorn , "John W. Linville" Subject: [09/53] rt2x00: Fix sleep-while-atomic bug in powersaving code. In-Reply-To: <20111123002419.GA8531@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gertjan van Wingerde commit ed66ba472a742cd8df37d7072804b2111cdb1014 upstream. The generic powersaving code that determines after reception of a frame whether the device should go back to sleep or whether is could stay awake was calling rt2x00lib_config directly from RX tasklet context. On a number of the devices this call can actually sleep, due to having to confirm that the sleeping commands have been executed successfully. Fix this by moving the call to rt2x00lib_config to a workqueue call. This fixes bug https://bugzilla.redhat.com/show_bug.cgi?id=731672 Tested-by: Tomas Trnka Signed-off-by: Gertjan van Wingerde Acked-by: Ivo van Doorn Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/rt2x00/rt2x00.h | 1 + drivers/net/wireless/rt2x00/rt2x00dev.c | 22 ++++++++++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-) --- a/drivers/net/wireless/rt2x00/rt2x00.h +++ b/drivers/net/wireless/rt2x00/rt2x00.h @@ -922,6 +922,7 @@ struct rt2x00_dev { * Powersaving work */ struct delayed_work autowakeup_work; + struct work_struct sleep_work; /* * Data queue arrays for RX, TX, Beacon and ATIM. --- a/drivers/net/wireless/rt2x00/rt2x00dev.c +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c @@ -449,6 +449,23 @@ static u8 *rt2x00lib_find_ie(u8 *data, u return NULL; } +static void rt2x00lib_sleep(struct work_struct *work) +{ + struct rt2x00_dev *rt2x00dev = + container_of(work, struct rt2x00_dev, sleep_work); + + if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags)) + return; + + /* + * Check again is powersaving is enabled, to prevent races from delayed + * work execution. + */ + if (!test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags)) + rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf, + IEEE80211_CONF_CHANGE_PS); +} + static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb, struct rxdone_entry_desc *rxdesc) @@ -496,8 +513,7 @@ static void rt2x00lib_rxdone_check_ps(st cam |= (tim_ie->bitmap_ctrl & 0x01); if (!cam && !test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags)) - rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf, - IEEE80211_CONF_CHANGE_PS); + queue_work(rt2x00dev->workqueue, &rt2x00dev->sleep_work); } static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev, @@ -1108,6 +1124,7 @@ int rt2x00lib_probe_dev(struct rt2x00_de INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled); INIT_DELAYED_WORK(&rt2x00dev->autowakeup_work, rt2x00lib_autowakeup); + INIT_WORK(&rt2x00dev->sleep_work, rt2x00lib_sleep); /* * Let the driver probe the device to detect the capabilities. @@ -1164,6 +1181,7 @@ void rt2x00lib_remove_dev(struct rt2x00_ */ cancel_work_sync(&rt2x00dev->intf_work); cancel_delayed_work_sync(&rt2x00dev->autowakeup_work); + cancel_work_sync(&rt2x00dev->sleep_work); if (rt2x00_is_usb(rt2x00dev)) { del_timer_sync(&rt2x00dev->txstatus_timer); cancel_work_sync(&rt2x00dev->rxdone_work);