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Commit ed66ba47 authored by Gertjan van Wingerde's avatar Gertjan van Wingerde Committed by John W. Linville
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rt2x00: Fix sleep-while-atomic bug in powersaving code. 

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: default avatarTomas Trnka <tomastrnka@gmx.com>
Signed-off-by: default avatarGertjan van Wingerde <gwingerde@gmail.com>
Cc: <stable@vger.kernel.org>
Acked-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent c18b7806

drivers/net/wireless/rt2x00/rt2x00.h

+1 −0
Original line number Diff line number Diff line
@@ -943,6 +943,7 @@ struct rt2x00_dev { 
	 * Powersaving work

	 */

	struct delayed_work autowakeup_work;

	struct work_struct sleep_work;



	/*

	 * Data queue arrays for RX, TX, Beacon and ATIM.

drivers/net/wireless/rt2x00/rt2x00dev.c

+20 −2
Original line number Diff line number Diff line
@@ -465,6 +465,23 @@ static u8 *rt2x00lib_find_ie(u8 *data, unsigned int len, u8 ie) 
	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)
@@ -512,8 +529,7 @@ static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev, 
	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,
@@ -1141,6 +1157,7 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev) 


	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.
@@ -1197,6 +1214,7 @@ void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev) 
	 */

	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);