Hi Sean,
Can you take a look at this, it appears to be an RC issue, see my analysis below.
On 10/20/2018 03:26 PM, Torbjorn Jansson wrote:
> Hello
>
> i'm using the pulse8 usb cec adapter to control my tv.
> i have a few scripts that poll the power status of my tv and after a while it stops working returning errors when trying to check if tv is on or off.
> this i think matches a kernel oops i'm seeing that i suspect is related to this.
>
> i have sometimes been able to recover from this problem by completely cutting power to my tv and also unplugging the usb cec adapter.
> i have a feeling that the tv is at least partly to blame for cec-ctl not working but in any case there shouldn't be a kernel oops.
>
>
> also every now and then i see this in dmesg:
> cec cec0: transmit: failed 05
> cec cec0: transmit: failed 06
> but that doesn't appear to do any harm as far as i can tell.
>
> any idea whats causing the oops?
>
> the ops:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
> PGD 0 P4D 0
> Oops: 0000 [#1] SMP PTI
> CPU: 9 PID: 27687 Comm: kworker/9:2 Tainted: P OE 4.18.12-200.fc28.x86_64 #1
> Hardware name: Supermicro C7X99-OCE-F/C7X99-OCE-F, BIOS 2.1a 06/15/2018
> Workqueue: events pulse8_irq_work_handler [pulse8_cec]
> RIP: 0010:ir_lirc_scancode_event+0x3d/0xb0 [rc_core]
Huh. ir_lirc_scancode_event() calls spin_lock_irqsave(&dev->lirc_fh_lock, flags);
The spinlock dev->lirc_fh_lock is initialized in ir_lirc_register(), which is called
from rc_register_device(), except when the protocol is CEC:
/* Ensure that the lirc kfifo is setup before we start the thread */
if (dev->allowed_protocols != RC_PROTO_BIT_CEC) {
rc = ir_lirc_register(dev);
if (rc < 0)
goto out_rx;
}
So it looks like ir_lirc_scancode_event() fails because dev->lirc_fh_lock was never
initialized.
Could this be fall-out from the lirc changes you did not too long ago?
Regards,
Hans
> Code: 8d ae b4 07 00 00 49 81 c6 b8 07 00 00 53 e8 4a df c3 d5 48 89 ef 49 89 45 00 e8 4e 84 41 d6 49 8b 1e 49 89 c4 4c 39 f3 74 58 <8b> 43 38 8b 53 40 89 c1 2b 4b 3c 39 ca 72 41 21 d0 49 8b 7d 00 49
> RSP: 0018:ffffaa10e3c07d58 EFLAGS: 00010017
> RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000018
> RDX: 0000000000000001 RSI: 00316245397fa93c RDI: ffff966d31c8d7b4
> RBP: ffff966d31c8d7b4 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000003 R11: ffffaa10e3c07e28 R12: 0000000000000002
> R13: ffffaa10e3c07d88 R14: ffff966d31c8d7b8 R15: 0000000000000073
> FS: 0000000000000000(0000) GS:ffff966d3f440000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000038 CR3: 00000009d820a003 CR4: 00000000003606e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> ir_do_keydown+0x75/0x260 [rc_core]
> rc_keydown+0x54/0xc0 [rc_core]
> cec_received_msg_ts+0xaa8/0xaf0 [cec]
> process_one_work+0x1a1/0x350
> worker_thread+0x30/0x380
> ? pwq_unbound_release_workfn+0xd0/0xd0
> kthread+0x112/0x130
> ? kthread_create_worker_on_cpu+0x70/0x70
> ret_from_fork+0x35/0x40
> Modules linked in: rc_tt_1500 dvb_usb_dvbsky dvb_usb_v2 uas usb_storage fuse vhost_net vhost tap xt_CHECKSUM iptable_mangle ip6t_REJECT nf_reject_ipv6 tun 8021q garp mrp xt_nat macvlan xfs devlink ebta
> si2157 si2168 cx25840 cx23885 kvm altera_ci tda18271 joydev ir_rc6_decoder rc_rc6_mce crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore altera_stapl m88ds3103 tveeprom cx2341
> mxm_wmi igb crc32c_intel megaraid_sas dca i2c_algo_bit wmi vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio i2c_dev
> CR2: 0000000000000038
> ---[ end trace 6cea307e2666b11a ]---
> RIP: 0010:ir_lirc_scancode_event+0x3d/0xb0 [rc_core]
> Code: 8d ae b4 07 00 00 49 81 c6 b8 07 00 00 53 e8 4a df c3 d5 48 89 ef 49 89 45 00 e8 4e 84 41 d6 49 8b 1e 49 89 c4 4c 39 f3 74 58 <8b> 43 38 8b 53 40 89 c1 2b 4b 3c 39 ca 72 41 21 d0 49 8b 7d 00 49
> RSP: 0018:ffffaa10e3c07d58 EFLAGS: 00010017
> RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000018
> RDX: 0000000000000001 RSI: 00316245397fa93c RDI: ffff966d31c8d7b4
> RBP: ffff966d31c8d7b4 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000003 R11: ffffaa10e3c07e28 R12: 0000000000000002
> R13: ffffaa10e3c07d88 R14: ffff966d31c8d7b8 R15: 0000000000000073
> FS: 0000000000000000(0000) GS:ffff966d3f440000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000038 CR3: 00000009d820a003 CR4: 00000000003606e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
