]> git.karo-electronics.de Git - linux-beck.git/commit
ath9k: Fix softlockup in AR9485
authorMohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Tue, 12 Jun 2012 14:43:43 +0000 (20:13 +0530)
committerJohn W. Linville <linville@tuxdriver.com>
Wed, 13 Jun 2012 18:35:57 +0000 (14:35 -0400)
commit64bc1239c790e051ff677e023435d770d2ffa174
tree6f71de3e35854e623bea91f29c171a54453e20b5
parenta197b76c230725962dc8e13102b24468e8621bfb
ath9k: Fix softlockup in AR9485

steps to recreate:
load latest ath9k driver with AR9485
stop the network-manager and wpa_supplicant
bring the interface up

Call Trace:
[<ffffffffa0517490>] ? ath_hw_check+0xe0/0xe0 [ath9k]
[<ffffffff812cd1e8>] __const_udelay+0x28/0x30
[<ffffffffa03bae7a>] ar9003_get_pll_sqsum_dvc+0x4a/0x80 [ath9k_hw]
[<ffffffffa05174eb>] ath_hw_pll_work+0x5b/0xe0 [ath9k]
[<ffffffff810744fe>] process_one_work+0x11e/0x470
[<ffffffff8107530f>] worker_thread+0x15f/0x360
[<ffffffff810751b0>] ? manage_workers+0x230/0x230
[<ffffffff81079af3>] kthread+0x93/0xa0
[<ffffffff815fd3a4>] kernel_thread_helper+0x4/0x10
[<ffffffff81079a60>] ? kthread_freezable_should_stop+0x70/0x70
[<ffffffff815fd3a0>] ? gs_change+0x13/0x13

ensure that the PLL-WAR for AR9485/AR9340 is executed only if the STA is
associated (or) IBSS/AP mode had started beaconing. Ideally this WAR
is needed to recover from some rare beacon stuck during stress testing.
Before the STA is associated/IBSS had started beaconing, PLL4(0x1618c)
always seem to have zero even though we had configured PLL3(0x16188) to
query about PLL's locking status. When we keep on polling infinitely PLL4's
8th bit(ie check for PLL locking measurements is done), machine hangs
due to softlockup.

fixes https://bugzilla.redhat.com/show_bug.cgi?id=811142

Reported-by: Rolf Offermanns <rolf.offermanns@gmx.net>
Cc: stable@vger.kernel.org
Tested-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/ath/ath9k/link.c