| Message ID | 3bf59b6c-f4be-1653-4f84-8668cf8581a1@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Heiner, On Sun, Feb 12, 2017 at 06:01:22PM +0100, Heiner Kallweit wrote: > nvt_write_wakeup_codes acquires the same lock as the ISR but doesn't > disable interrupts on the local CPU. This caused the following > deadlock. Fix this by using spin_lock_irqsave. > > [ 432.362008] ================================ > [ 432.362074] WARNING: inconsistent lock state > [ 432.362144] 4.10.0-rc7-next-20170210 #1 Not tainted > [ 432.362219] -------------------------------- -snip- Thank you for that, I'll make a pull request soon so we have it for 4.11. Would you mind testing the new wakeup_protocols interface on the nuvoton please? cd /sys/class/rc/rc0 echo rc-5 > wakeup_protocols echo 0xffff > wakeup_filter_mask echo 0x1e01 > wakeup_filter (replace as needed) Thanks! Sean
diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c index b109f824..ec4b25bd 100644 --- a/drivers/media/rc/nuvoton-cir.c +++ b/drivers/media/rc/nuvoton-cir.c @@ -176,12 +176,13 @@ static void nvt_write_wakeup_codes(struct rc_dev *dev, { u8 tolerance, config; struct nvt_dev *nvt = dev->priv; + unsigned long flags; int i; /* hardcode the tolerance to 10% */ tolerance = DIV_ROUND_UP(count, 10); - spin_lock(&nvt->lock); + spin_lock_irqsave(&nvt->lock, flags); nvt_clear_cir_wake_fifo(nvt); nvt_cir_wake_reg_write(nvt, count, CIR_WAKE_FIFO_CMP_DEEP); @@ -203,7 +204,7 @@ static void nvt_write_wakeup_codes(struct rc_dev *dev, nvt_cir_wake_reg_write(nvt, config, CIR_WAKE_IRCON); - spin_unlock(&nvt->lock); + spin_unlock_irqrestore(&nvt->lock, flags); } static ssize_t wakeup_data_show(struct device *dev,
nvt_write_wakeup_codes acquires the same lock as the ISR but doesn't disable interrupts on the local CPU. This caused the following deadlock. Fix this by using spin_lock_irqsave. [ 432.362008] ================================ [ 432.362074] WARNING: inconsistent lock state [ 432.362144] 4.10.0-rc7-next-20170210 #1 Not tainted [ 432.362219] -------------------------------- [ 432.362286] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. [ 432.362379] swapper/0/0 [HC1[1]:SC0[0]:HE0:SE1] takes: [ 432.362457] (&(&nvt->lock)->rlock){?.+...}, at: [<ffffffffa016b17d>] nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.362611] {HARDIRQ-ON-W} state was registered at: [ 432.362686] [ 432.362698] [<ffffffff810adb7c>] __lock_acquire+0x5dc/0x1260 [ 432.362812] [ 432.362817] [<ffffffff810aec29>] lock_acquire+0xe9/0x1d0 [ 432.362927] [ 432.362934] [<ffffffff81609f63>] _raw_spin_lock+0x33/0x50 [ 432.363045] [ 432.363051] [<ffffffffa016b822>] nvt_write_wakeup_codes.isra.12+0x22/0xe0 [nuvoton_cir] [ 432.363193] [ 432.363199] [<ffffffffa016b9bf>] wakeup_data_store+0xdf/0xf0 [nuvoton_cir] [ 432.363327] [ 432.363333] [<ffffffff81484223>] dev_attr_store+0x13/0x20 [ 432.363441] [ 432.363449] [<ffffffff81232450>] sysfs_kf_write+0x40/0x50 [ 432.363558] [ 432.363564] [<ffffffff81231640>] kernfs_fop_write+0x150/0x1e0 [ 432.363676] [ 432.363685] [<ffffffff811b36a3>] __vfs_write+0x23/0x120 [ 432.363791] [ 432.363798] [<ffffffff811b4d53>] vfs_write+0xc3/0x1e0 [ 432.363902] [ 432.363909] [<ffffffff811b6124>] SyS_write+0x44/0xa0 [ 432.364012] [ 432.364021] [<ffffffff81002c47>] do_syscall_64+0x57/0x140 [ 432.364129] [ 432.364135] [<ffffffff8160a9e4>] return_from_SYSCALL_64+0x0/0x7a [ 432.364252] irq event stamp: 415118 [ 432.364313] hardirqs last enabled at (415115): [<ffffffff814fd2eb>] cpuidle_enter_state+0x11b/0x370 [ 432.364445] hardirqs last disabled at (415116): [<ffffffff8160b2cb>] common_interrupt+0x8b/0x90 [ 432.364573] softirqs last enabled at (415118): [<ffffffff8106157c>] _local_bh_enable+0x1c/0x50 [ 432.364699] softirqs last disabled at (415117): [<ffffffff810629a3>] irq_enter+0x43/0x60 [ 432.364814] other info that might help us debug this: [ 432.364909] Possible unsafe locking scenario: [ 432.367821] CPU0 [ 432.370645] ---- [ 432.373432] lock(&(&nvt->lock)->rlock); [ 432.376228] <Interrupt> [ 432.378982] lock(&(&nvt->lock)->rlock); [ 432.381757] *** DEADLOCK *** [ 432.389888] no locks held by swapper/0/0. [ 432.392574] stack backtrace: [ 432.397774] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-rc7-next-20170210 #1 [ 432.400375] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015 [ 432.403023] Call Trace: [ 432.405636] <IRQ> [ 432.408208] dump_stack+0x68/0x93 [ 432.410775] print_usage_bug+0x1dd/0x1f0 [ 432.413334] mark_lock+0x559/0x5c0 [ 432.415871] ? print_shortest_lock_dependencies+0x1a0/0x1a0 [ 432.418431] __lock_acquire+0x6b1/0x1260 [ 432.420941] lock_acquire+0xe9/0x1d0 [ 432.423396] ? nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.425844] _raw_spin_lock+0x33/0x50 [ 432.428252] ? nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.430670] nvt_cir_isr+0x2d/0x520 [nuvoton_cir] [ 432.433085] __handle_irq_event_percpu+0x43/0x330 [ 432.435493] handle_irq_event_percpu+0x1e/0x50 [ 432.437884] handle_irq_event+0x34/0x60 [ 432.440236] handle_edge_irq+0x6a/0x150 [ 432.442561] handle_irq+0x15/0x20 [ 432.444854] do_IRQ+0x57/0x110 [ 432.447115] common_interrupt+0x90/0x90 [ 432.449380] RIP: 0010:cpuidle_enter_state+0x120/0x370 [ 432.451653] RSP: 0018:ffffffff81c03dd8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffffcc [ 432.453994] RAX: ffffffff81c14500 RBX: 0000000000000008 RCX: 00000064aac6f2d2 [ 432.456349] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff81c14500 [ 432.458704] RBP: ffffffff81c03e18 R08: cccccccccccccccd R09: 0000000000000018 [ 432.461072] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880100a21260 [ 432.463450] R13: ffffffff81c7e6f8 R14: 0000000000000008 R15: ffffffff81c7e6e0 [ 432.465819] </IRQ> [ 432.468104] ? cpuidle_enter_state+0x11b/0x370 [ 432.470413] cpuidle_enter+0x12/0x20 [ 432.472698] call_cpuidle+0x1e/0x40 [ 432.474967] do_idle+0xe3/0x1c0 [ 432.477172] cpu_startup_entry+0x18/0x20 [ 432.479376] rest_init+0x130/0x140 [ 432.481565] start_kernel+0x3cc/0x3d9 [ 432.483750] x86_64_start_reservations+0x2a/0x2c [ 432.485980] x86_64_start_kernel+0x178/0x18b [ 432.488222] start_cpu+0x14/0x14 [ 432.490453] ? start_cpu+0x14/0x14 Fixes: 97c129747af5 "[media] rc: nuvoton-cir: Add support wakeup via sysfs filter callback" Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/media/rc/nuvoton-cir.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)