[ 005/108] rtl8187: ->brightness_set can not sleep

From: Ben Hutchings
Date: Sun Jul 22 2012 - 22:08:59 EST

3.2-stable review patch. If anyone has any objections, please let me know.


From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit 0fde0a8cfd0ede7f310d6a681c8e5a7cb3e32406 upstream.


BUG: sleeping function called from invalid context at kernel/workqueue.c:2547
in_atomic(): 1, irqs_disabled(): 0, pid: 629, name: wpa_supplicant
2 locks held by wpa_supplicant/629:
#0: (rtnl_mutex){+.+.+.}, at: [<c08b2b84>] rtnl_lock+0x14/0x20
#1: (&trigger->leddev_list_lock){.+.?..}, at: [<c0867f41>] led_trigger_event+0x21/0x80
Pid: 629, comm: wpa_supplicant Not tainted 3.3.0-0.rc3.git5.1.fc17.i686
Call Trace:
[<c046a9f6>] __might_sleep+0x126/0x1d0
[<c0457d6c>] wait_on_work+0x2c/0x1d0
[<c045a09a>] __cancel_work_timer+0x6a/0x120
[<c045a160>] cancel_delayed_work_sync+0x10/0x20
[<f7dd3c22>] rtl8187_led_brightness_set+0x82/0xf0 [rtl8187]
[<c0867f7c>] led_trigger_event+0x5c/0x80
[<f7ff5e6d>] ieee80211_led_radio+0x1d/0x40 [mac80211]
[<f7ff3583>] ieee80211_stop_device+0x13/0x230 [mac80211]

Removing _sync is ok, because if led_on work is currently running
it will be finished before led_off work start to perform, since
they are always queued on the same mac80211 local->workqueue.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=795176

Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Acked-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
Acked-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/net/wireless/rtl818x/rtl8187/leds.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rtl818x/rtl8187/leds.c b/drivers/net/wireless/rtl818x/rtl8187/leds.c
index 2e0de2f..c2d5b49 100644
--- a/drivers/net/wireless/rtl818x/rtl8187/leds.c
+++ b/drivers/net/wireless/rtl818x/rtl8187/leds.c
@@ -117,7 +117,7 @@ static void rtl8187_led_brightness_set(struct led_classdev *led_dev,
radio_on = true;
} else if (radio_on) {
radio_on = false;
- cancel_delayed_work_sync(&priv->led_on);
+ cancel_delayed_work(&priv->led_on);
ieee80211_queue_delayed_work(hw, &priv->led_off, 0);
} else if (radio_on) {

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