On Wed, May 03, 2017 at 12:04:00PM +0200, David Härdeman wrote: > The device core infrastructure is based on the presumption that > once a driver calls device_add(), it must be ready to accept > userspace interaction. > > This requires splitting rc_setup_rx_device() into two functions > and reorganizing rc_register_device() so that as much work > as possible is performed before calling device_add(). > > Version 2: switch the order in which rc_prepare_rx_device() and > ir_raw_event_prepare() gets called so that dev->change_protocol() > gets called before device_add(). With this patch applied, when I plug in an iguanair usb device, I get. (The raw rc thread has not been started when the input device is registered.) [ 65.875642] usb 7-1.3: new low-speed USB device number 6 using uhci_hcd [ 66.004105] usb 7-1.3: New USB device found, idVendor=1781, idProduct=0938 [ 66.004111] usb 7-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 66.004116] usb 7-1.3: Product: USB IR Transceiver [ 66.004120] usb 7-1.3: Manufacturer: IguanaWorks [ 66.057190] Registered IR keymap rc-rc6-mce [ 66.057328] rc rc1: IguanaWorks USB IR Transceiver version 0x0308 as /devices/pci0000:00/0000:00:1d.1/usb7/7-1/7-1.3/7-1.3:1.0/rc/rc1 [ 66.057423] input: IguanaWorks USB IR Transceiver version 0x0308 as /devices/pci0000:00/0000:00:1d.1/usb7/7-1/7-1.3/7-1.3:1.0/rc/rc1/input24 [ 66.057445] BUG: unable to handle kernel NULL pointer dereference at 0000000000000ba0 [ 66.057500] IP: __lock_acquire+0x122/0x12e0 [ 66.057522] PGD 0 [ 66.057523] P4D 0 [ 66.057556] Oops: 0000 [#1] SMP [ 66.057573] Modules linked in: iguanair(+) mceusb xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun fuse nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_security ip6table_mangle ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_security iptable_mangle iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables snd_hda_codec_idt snd_hda_codec_generic tuner_simple tuner_types wm8775 tda9887 tda8290 tuner coretemp kvm_intel ppdev cx25840 mei_wdt kvm iTCO_wdt iTCO_vendor_support ivtv snd_hda_codec_hdmi irqbypass snd_hda_intel joydev snd_hda_codec tveeprom [ 66.057945] cx2341x v4l2_common snd_hda_core pcspkr videodev snd_hwdep i2c_i801 snd_seq media ir_rc6_decoder snd_seq_device rc_rc6_mce ir_lirc_codec snd_pcm lirc_dev winbond_cir rc_core mei_me snd_timer snd shpchp mei video parport_pc nfsd soundcore parport acpi_cpufreq tpm_tis tpm_tis_core tpm lpc_ich auth_rpcgss nfs_acl lockd grace sunrpc amdkfd amd_iommu_v2 amdgpu i2c_algo_bit drm_kms_helper syscopyarea sysfillrect e1000e sysimgblt fb_sys_fops ttm hid_sjoy ff_memless firewire_ohci firewire_core drm serio_raw ata_generic pata_acpi crc_itu_t ptp pps_core [ 66.058080] CPU: 3 PID: 2092 Comm: systemd-udevd Not tainted 4.12.0-rc1+ #1 [ 66.058080] Hardware name: /DG45ID, BIOS IDG4510H.86A.0135.2011.0225.1100 02/25/2011 [ 66.058080] task: ffff88bb9e34c000 task.stack: ffffa014c071c000 [ 66.058080] RIP: 0010:__lock_acquire+0x122/0x12e0 [ 66.058080] RSP: 0018:ffffa014c071f720 EFLAGS: 00010002 [ 66.058080] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 [ 66.058080] RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000000 [ 66.058080] RBP: ffffa014c071f7e0 R08: ffffffff9b0be570 R09: 0000000000000001 [ 66.058080] R10: 0000000000000000 R11: ffff88bb9e34c000 R12: 0000000000000001 [ 66.058080] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000ba0 [ 66.058080] FS: 00007f7be5e84640(0000) GS:ffff88bbabd80000(0000) knlGS:0000000000000000 [ 66.058080] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.058080] CR2: 0000000000000ba0 CR3: 000000021bb83000 CR4: 00000000000006e0 [ 66.058080] Call Trace: [ 66.058080] lock_acquire+0xc7/0x1a0 [ 66.058080] ? lock_acquire+0xc7/0x1a0 [ 66.058080] ? try_to_wake_up+0x40/0x500 [ 66.058080] _raw_spin_lock_irqsave+0x33/0x50 [ 66.058080] ? try_to_wake_up+0x40/0x500 [ 66.058080] try_to_wake_up+0x40/0x500 [ 66.058080] ? input_open_device+0x28/0xa0 [ 66.058080] ? __mutex_lock+0x75/0x970 [ 66.058080] ? rc_open+0x2a/0x80 [rc_core] [ 66.058080] wake_up_process+0x15/0x20 [ 66.058080] ir_raw_event_handle+0x1e/0x20 [rc_core] [ 66.058080] iguanair_receiver+0x6c/0xa0 [iguanair] [ 66.058080] iguanair_open+0x30/0x50 [iguanair] [ 66.058080] rc_open+0x4e/0x80 [rc_core] [ 66.058080] ir_open+0x15/0x20 [rc_core] [ 66.058080] input_open_device+0x7b/0xa0 [ 66.058080] kbd_connect+0x73/0x90 [ 66.058080] ? trace_hardirqs_on_caller+0xed/0x180 [ 66.058080] input_attach_handler+0x1a2/0x1e0 [ 66.058080] input_register_device+0x483/0x530 [ 66.058080] rc_register_device+0x47e/0x590 [rc_core] [ 66.058080] iguanair_probe+0x500/0x610 [iguanair] [ 66.058080] usb_probe_interface+0x15f/0x2d0 [ 66.058080] driver_probe_device+0x29c/0x450 [ 66.058080] __driver_attach+0xe3/0xf0 [ 66.058080] ? driver_probe_device+0x450/0x450 [ 66.058080] bus_for_each_dev+0x73/0xc0 [ 66.058080] driver_attach+0x1e/0x20 [ 66.058080] bus_add_driver+0x173/0x270 [ 66.058080] driver_register+0x60/0xe0 [ 66.058080] usb_register_driver+0xaa/0x160 [ 66.058080] ? 0xffffffffc0349000 [ 66.058080] iguanair_driver_init+0x1e/0x1000 [iguanair] [ 66.058080] do_one_initcall+0x52/0x190 [ 66.058080] ? rcu_read_lock_sched_held+0x5d/0x70 [ 66.058080] ? kmem_cache_alloc_trace+0x1f4/0x260 [ 66.058080] ? do_init_module+0x27/0x1fa [ 66.058080] do_init_module+0x5f/0x1fa [ 66.058080] load_module+0x2823/0x2cd0 [ 66.058080] ? vfs_read+0x11b/0x130 [ 66.058080] SYSC_finit_module+0xdf/0x110 [ 66.058080] ? SYSC_finit_module+0xdf/0x110 [ 66.058080] SyS_finit_module+0xe/0x10 [ 66.058080] entry_SYSCALL_64_fastpath+0x18/0xad [ 66.058080] RIP: 0033:0x7f7be4afebf9 [ 66.058080] RSP: 002b:00007ffc1e53d558 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 66.058080] RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f7be4afebf9 [ 66.058080] RDX: 0000000000000000 RSI: 00007f7be5637995 RDI: 0000000000000007 [ 66.058080] RBP: 0000000000000005 R08: 0000000000000000 R09: 00007ffc1e53d670 [ 66.058080] R10: 0000000000000007 R11: 0000000000000246 R12: 00007ffc1e53c550 [ 66.058080] R13: 00007ffc1e53c530 R14: 0000000000000005 R15: 000055f1457d53d0 [ 66.058080] Code: c8 65 48 33 34 25 28 00 00 00 44 89 f0 0f 85 26 0d 00 00 48 81 c4 90 00 00 00 5b 41 5a 41 5c 41 5d 41 5e 41 5f 5d 49 8d 62 f8 c3 <49> 81 3f 80 a9 2e 9c 41 bc 00 00 00 00 44 0f 45 e0 83 fe 01 0f [ 66.058080] RIP: __lock_acquire+0x122/0x12e0 RSP: ffffa014c071f720 [ 66.058080] CR2: 0000000000000ba0 [ 66.058080] ---[ end trace a40e73805c213cce ]---
