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author | Emil Goode <emilgoode@gmail.com> | 2014-03-10 00:06:51 +0400 |
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committer | Jiri Slaby <jslaby@suse.cz> | 2014-04-25 20:10:04 +0400 |
commit | de0b7b0dd1b625c8b4730869ae3d651e9189617c (patch) | |
tree | b6e47f1d7a071cc43a3fe025279dcdc21f9d4c61 /drivers/char | |
parent | 7d4f4737432af6216e86975e587331b9d8b08063 (diff) | |
download | linux-de0b7b0dd1b625c8b4730869ae3d651e9189617c.tar.xz |
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: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'drivers/char')
0 files changed, 0 insertions, 0 deletions