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authorLarry Finger <Larry.Finger@lwfinger.net>2014-01-12 15:11:37 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-06 11:05:47 -0800
commit4dbfb7dd725b29e1aa1bbe2db6aadaf6d825b9c4 (patch)
treea50bded751f09606995d4b0e68cba6f3cb81d665 /drivers
parent2ef4b350117b132da638064241c0d1e4a05e3408 (diff)
b43: Fix lockdep splat
commit 09164043f63c947a49797750a09ca1cd7c31108e upstream. In https://bugzilla.kernel.org/show_bug.cgi?id=67561, a locking dependency is reported when b43 is used with hostapd, and rfkill is used to kill the radio output. The lockdep splat (in part) is as follows: ====================================================== [ INFO: possible circular locking dependency detected ] 3.12.0 #1 Not tainted ------------------------------------------------------- rfkill/10040 is trying to acquire lock: (rtnl_mutex){+.+.+.}, at: [<ffffffff8146f282>] rtnl_lock+0x12/0x20 but task is already holding lock: (rfkill_global_mutex){+.+.+.}, at: [<ffffffffa04832ca>] rfkill_fop_write+0x6a/0x170 [rfkill] --snip-- Chain exists of: rtnl_mutex --> misc_mtx --> rfkill_global_mutex The fix is to move the initialization of the hardware random number generator outside the code range covered by the rtnl_mutex. Reported-by: yury <urykhy@gmail.com> Tested-by: yury <urykhy@gmail.com> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/wireless/b43/main.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index f8c4499cf644..3a2d6726de55 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2413,6 +2413,7 @@ error:
static int b43_one_core_attach(struct b43_bus_dev *dev, struct b43_wl *wl);
static void b43_one_core_detach(struct b43_bus_dev *dev);
+static int b43_rng_init(struct b43_wl *wl);
static void b43_request_firmware(struct work_struct *work)
{
@@ -2459,6 +2460,10 @@ start_ieee80211:
if (err)
goto err_one_core_detach;
b43_leds_register(wl->current_dev);
+
+ /* Register HW RNG driver */
+ b43_rng_init(wl);
+
goto out;
err_one_core_detach:
@@ -4583,9 +4588,6 @@ static void b43_wireless_core_exit(struct b43_wldev *dev)
if (!dev || b43_status(dev) != B43_STAT_INITIALIZED)
return;
- /* Unregister HW RNG driver */
- b43_rng_exit(dev->wl);
-
b43_set_status(dev, B43_STAT_UNINIT);
/* Stop the microcode PSM. */
@@ -4728,9 +4730,6 @@ static int b43_wireless_core_init(struct b43_wldev *dev)
b43_set_status(dev, B43_STAT_INITIALIZED);
- /* Register HW RNG driver */
- b43_rng_init(dev->wl);
-
out:
return err;
@@ -5388,6 +5387,9 @@ static void b43_bcma_remove(struct bcma_device *core)
b43_one_core_detach(wldev->dev);
+ /* Unregister HW RNG driver */
+ b43_rng_exit(wl);
+
b43_leds_unregister(wl);
ieee80211_free_hw(wl->hw);
@@ -5468,6 +5470,9 @@ static void b43_ssb_remove(struct ssb_device *sdev)
b43_one_core_detach(dev);
+ /* Unregister HW RNG driver */
+ b43_rng_exit(wl);
+
if (list_empty(&wl->devlist)) {
b43_leds_unregister(wl);
/* Last core on the chip unregistered.