From e0d1c1de5638a4fffbc9d5d9f141c434531dc3b9 Mon Sep 17 00:00:00 2001 From: Mohammed Shafi Shajakhan Date: Wed, 13 Jun 2012 21:28:09 +0530 Subject: ath9k: Fix softlockup in AR9485 commit bcb7ad7bcbef030e6ba71ede1f9866368aca7c99 upstream. steps to recreate: load latest ath9k driver with AR9485 stop the network-manager and wpa_supplicant bring the interface up Call Trace: [] ? ath_hw_check+0xe0/0xe0 [ath9k] [] __const_udelay+0x28/0x30 [] ar9003_get_pll_sqsum_dvc+0x4a/0x80 [ath9k_hw] [] ath_hw_pll_work+0x5b/0xe0 [ath9k] [] process_one_work+0x11e/0x470 [] worker_thread+0x15f/0x360 [] ? manage_workers+0x230/0x230 [] kthread+0x93/0xa0 [] kernel_thread_helper+0x4/0x10 [] ? kthread_freezable_should_stop+0x70/0x70 [] ? 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 Tested-by: Mohammed Shafi Shajakhan Signed-off-by: Mohammed Shafi Shajakhan Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/ath/ath9k/main.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/net/wireless') diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c index 42e3f427c74..d5dabcb61a0 100644 --- a/drivers/net/wireless/ath/ath9k/main.c +++ b/drivers/net/wireless/ath/ath9k/main.c @@ -960,6 +960,15 @@ void ath_hw_pll_work(struct work_struct *work) hw_pll_work.work); u32 pll_sqsum; + /* + * ensure that the PLL WAR is executed only + * after the STA is associated (or) if the + * beaconing had started in interfaces that + * uses beacons. + */ + if (!(sc->sc_flags & SC_OP_BEACONS)) + return; + if (AR_SREV_9485(sc->sc_ah)) { ath9k_ps_wakeup(sc); -- cgit v1.2.3