Tobias Klausmann <tobias.johannes.klausmann@xxxxxxxxxx> wrote: > Starting with commit d94a461d7a7d ("ath9k: use ieee80211_tx_status_noskb > where possible") the driver uses rcu_read_lock() && rcu_read_unlock(), yet on > returning early in ath_tx_edma_tasklet() the unlock is missing leading to stalls > and suspicious RCU usage: > > =============================== > [ INFO: suspicious RCU usage. ] > 4.9.0-rc8 #11 Not tainted > ------------------------------- > kernel/rcu/tree.c:705 Illegal idle entry in RCU read-side critical section.! > > other info that might help us debug this: > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 1 lock held by swapper/7/0: > #0: > ( > rcu_read_lock > ){......} > , at: > [<ffffffffa06ed110>] ath_tx_edma_tasklet+0x0/0x450 [ath9k] > > stack backtrace: > CPU: 7 PID: 0 Comm: swapper/7 Not tainted 4.9.0-rc8 #11 > Hardware name: Acer Aspire V3-571G/VA50_HC_CR, BIOS V2.21 12/16/2013 > ffff88025efc3f38 ffffffff8132b1e5 ffff88017ede4540 0000000000000001 > ffff88025efc3f68 ffffffff810a25f7 ffff88025efcee60 ffff88017edebdd8 > ffff88025eeb5400 0000000000000091 ffff88025efc3f88 ffffffff810c3cd4 > Call Trace: > <IRQ> > [<ffffffff8132b1e5>] dump_stack+0x68/0x93 > [<ffffffff810a25f7>] lockdep_rcu_suspicious+0xd7/0x110 > [<ffffffff810c3cd4>] rcu_eqs_enter_common.constprop.85+0x154/0x200 > [<ffffffff810c5a54>] rcu_irq_exit+0x44/0xa0 > [<ffffffff81058631>] irq_exit+0x61/0xd0 > [<ffffffff81018d25>] do_IRQ+0x65/0x110 > [<ffffffff81672189>] common_interrupt+0x89/0x89 > <EOI> > [<ffffffff814ffe11>] ? cpuidle_enter_state+0x151/0x200 > [<ffffffff814ffee2>] cpuidle_enter+0x12/0x20 > [<ffffffff8109a6ae>] call_cpuidle+0x1e/0x40 > [<ffffffff8109a8f6>] cpu_startup_entry+0x146/0x220 > [<ffffffff810336f8>] start_secondary+0x148/0x170 > > Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@xxxxxxxxxx> > Fixes: d94a461d7a7d ("ath9k: use ieee80211_tx_status_noskb where possible") > Cc: <stable@xxxxxxxxxxxxxxx> # v4.9 > Acked-by: Felix Fietkau <nbd@xxxxxxxx> Patch applied to ath-current branch of ath.git, thanks. d1f1c0e289e1 ath9k: do not return early to fix rcu unlocking -- https://patchwork.kernel.org/patch/9472709/ Documentation about submitting wireless patches and checking status from patchwork: https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html