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    Subject[10/53] rt2x00: Fix sleep-while-atomic bug in powersaving code.
    3.1-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Gertjan van Wingerde <gwingerde@gmail.com>

    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 <tomastrnka@gmx.com>
    Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
    Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
    Signed-off-by: John W. Linville <linville@tuxdriver.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    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
    @@ -923,6 +923,7 @@ 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,
    @@ -1121,6 +1137,7 @@ 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.
    @@ -1177,6 +1194,7 @@ 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);



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