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| author | Emil Goode <emilgoode@gmail.com> | 2014-03-09 21:06:51 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-07 13:25:34 -0700 |
| commit | b020ee793f714e7d293078a1e0ea8a545c33b16f (patch) | |
| tree | fa859c3120db7ebaf96a39ed7c2e0a32e86b8af2 | |
| parent | 5d33fff5ca9aab5ae7d28fc06179a91eb529758e (diff) | |
| download | lwn-b020ee793f714e7d293078a1e0ea8a545c33b16f.tar.gz lwn-b020ee793f714e7d293078a1e0ea8a545c33b16f.zip | |
brcmsmac: fix deadlock on missing firmware
commit 8fc1e8c240aab968db658b2d8d079b4391207a36 upstream.
When brcm80211 firmware is not installed networking hangs.
A deadlock happens because we call ieee80211_unregister_hw()
from the .start callback of struct ieee80211_ops. When .start
is called we are under rtnl lock and ieee80211_unregister_hw()
tries to take it again.
Function call stack:
dev_change_flags()
__dev_change_flags()
__dev_open()
ASSERT_RTNL() <-- Assert rtnl lock
ops->ndo_open()
.ndo_open = ieee80211_open,
ieee80211_open()
ieee80211_do_open()
drv_start()
local->ops->start()
.start = brcms_ops_start,
brcms_ops_start()
brcms_remove()
ieee80211_unregister_hw()
rtnl_lock() <-- Here we deadlock
Introduced by:
commit 25b5632fb35ca61b8ae3eee235edcdc2883f7a5e
("brcmsmac: request firmware in .start() callback")
This patch fixes the bug by removing the call to brcms_remove()
and moves the brcms_request_fw() call to the top of the .start
callback to not initiate anything unless firmware is installed.
Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c index 3a6544710c8a..8e8543cfe489 100644 --- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c +++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c @@ -426,6 +426,12 @@ static int brcms_ops_start(struct ieee80211_hw *hw) bool blocked; int err; + if (!wl->ucode.bcm43xx_bomminor) { + err = brcms_request_fw(wl, wl->wlc->hw->d11core); + if (err) + return -ENOENT; + } + ieee80211_wake_queues(hw); spin_lock_bh(&wl->lock); blocked = brcms_rfkill_set_hw_state(wl); @@ -433,14 +439,6 @@ static int brcms_ops_start(struct ieee80211_hw *hw) if (!blocked) wiphy_rfkill_stop_polling(wl->pub->ieee_hw->wiphy); - if (!wl->ucode.bcm43xx_bomminor) { - err = brcms_request_fw(wl, wl->wlc->hw->d11core); - if (err) { - brcms_remove(wl->wlc->hw->d11core); - return -ENOENT; - } - } - spin_lock_bh(&wl->lock); /* avoid acknowledging frames before a non-monitor device is added */ wl->mute_tx = true; |