我正在尝试为phytec板上的CSR8811芯片组启用蓝牙接口（imx6ul臂）。内核是4.8 我在执行操作时遇到了异常：
# hciattach /dev/ttyACM0 bcsp
# hciattach /dev/ttyACM0 bcsp
[ 157.902406] INFO: rcu_sched self-detected stall on CPU
[ 157.907628] 0-...: (2600 ticks this GP) idle=21b/140000000000002/0 softirq=8480/8480 fqs=0
[ 157.916085] (t=2600 jiffies g=4247 c=4246 q=48)
[ 157.920841] rcu_sched kthread starved for 2600 jiffies! g4247 c4246 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x1
[ 157.930253] rcu_sched S c0905b98 0 7 2 0x00000000
[ 157.936673] Backtrace:
[ 157.939180] [<c090594c>] (__schedule) from [<c09060dc>] (schedule+0x48/0xa0)
[ 157.946247] r10:dffc84c0 r9:ffffffff r8:c0e02100 r7:00000000 r6:de48bea0 r5:dffc84c0
[ 157.954204] r4:de48a000
[ 157.956787] [<c0906094>] (schedule) from [<c090a998>] (schedule_timeout+0x218/0x318)
[ 157.964543] r5:dffc84c0 r4:ffffbe56
[ 157.968193] [<c090a780>] (schedule_timeout) from [<c018a31c>] (rcu_gp_kthread+0x4f0/0x840)
[ 157.976472] r10:c0e15680 r9:00000000 r8:00000001 r7:00000001 r6:c0e156d0 r5:c0e156f8
[ 157.984429] r4:c0e15440
[ 157.987013] [<c0189e2c>] (rcu_gp_kthread) from [<c0145ddc>] (kthread+0xdc/0xf8)
[ 157.994336] r7:c0189e2c
[ 157.996919] [<c0145d00>] (kthread) from [<c0107eb0>] (ret_from_fork+0x14/0x24)
[ 158.004155] r7:00000000 r6:00000000 r5:c0145d00 r4:de435040
[ 158.009977] Task dump for CPU 0:
[ 158.013230] hciattach R running 0 856 847 0x00000003
[ 158.019646] Backtrace:
[ 158.022146] [<c010c46c>] (dump_backtrace) from [<c010c664>] (show_stack+0x18/0x1c)
[ 158.029734] r7:00000240 r6:c0e6db57 r5:0000034f r4:ddfd4800
[ 158.035507] [<c010c64c>] (show_stack) from [<c015101c>] (sched_show_task+0x11c/0x22c)
[ 158.043368] [<c0150f00>] (sched_show_task) from [<c0153d14>] (dump_cpu_task+0x34/0x44)
[ 158.051298] r6:c0e15440 r5:00000000 r4:00000000
[ 158.056008] [<c0153ce0>] (dump_cpu_task) from [<c01cf058>] (rcu_dump_cpu_stacks+0xa4/0xc8)
[ 158.064286] r5:00000000 r4:c0e15440
[ 158.067930] [<c01cefb4>] (rcu_dump_cpu_stacks) from [<c018b258>] (rcu_check_callbacks+0x6f4/0x8b4)
[ 158.076902] r9:c0e15d44 r8:c0e02b18 r7:1f256000 r6:c0d76180 r5:dffcc180 r4:c0e15440
[ 158.084789] [<c018ab64>] (rcu_check_callbacks) from [<c018e5c8>] (update_process_times+0x38/0x64)
[ 158.093675] r10:c01a15c8 r9:dffc964c r8:dffc9640 r7:00000024 r6:c2fb3fd3 r5:00000000
[ 158.101630] r4:ddfd4800
[ 158.104214] [<c018e590>] (update_process_times) from [<c01a15c4>] (tick_sched_handle+0x50/0x54)
[ 158.112927] r5:dd8ff940 r4:dffc9908
[ 158.116570] [<c01a1574>] (tick_sched_handle) from [<c01a1628>] (tick_sched_timer+0x60/0xac)
[ 158.124951] [<c01a15c8>] (tick_sched_timer) from [<c018f5b4>] (__hrtimer_run_queues+0xc8/0x1e4)
[ 158.133662] r7:00000000 r6:c0e22828 r5:dffc9908 r4:dffc95c0
[ 158.139440] [<c018f4ec>] (__hrtimer_run_queues) from [<c018f8e4>] (hrtimer_interrupt+0xbc/0x210)
[ 158.148241] r10:dffc9678 r9:dffc9698 r8:dffc9600 r7:dffc96b8 r6:ffffffff r5:00000003
[ 158.156196] r4:dffc95c0
[ 158.158781] [<c018f828>] (hrtimer_interrupt) from [<c06b7c5c>] (mxc_timer_interrupt+0x3c/0x44)
[ 158.167408] r10:c0e6db92 r9:de41d000 r8:00000010 r7:dd8ff874 r6:00000000 r5:de41d000
[ 158.175365] r4:de402440
[ 158.177949] [<c06b7c20>] (mxc_timer_interrupt) from [<c017c4c0>] (__handle_irq_event_percpu+0x8c/0x124)
[ 158.187356] r5:de41d000 r4:de402500
[ 158.191001] [<c017c434>] (__handle_irq_event_percpu) from [<c017c57c>] (handle_irq_event_percpu+0x24/0x60)
[ 158.200668] r10:00000000 r9:de406000 r8:00000001 r7:dd8ffad0 r6:c0e10120 r5:de41d000
[ 158.208622] r4:de41d000
[ 158.211201] [<c017c558>] (handle_irq_event_percpu) from [<c017c5f8>] (handle_irq_event+0x40/0x64)
[ 158.220086] r5:de41d060 r4:de41d000
[ 158.223728] [<c017c5b8>] (handle_irq_event) from [<c017fd74>] (handle_fasteoi_irq+0xd4/0x1ac)
[ 158.232266] r7:dd8ffad0 r6:c0e10120 r5:de41d060 r4:de41d000
[ 158.238045] [<c017fca0>] (handle_fasteoi_irq) from [<c017b9cc>] (generic_handle_irq+0x28/0x3c)
[ 158.246671] r7:dd8ffad0 r6:c0e02b18 r5:00000010 r4:c0d73fa4
[ 158.252449] [<c017b9a4>] (generic_handle_irq) from [<c017bd24>] (__handle_domain_irq+0x6c/0xe8)
[ 158.261177] [<c017bcb8>] (__handle_domain_irq) from [<c01015f8>] (gic_handle_irq+0x58/0xb8)
[ 158.269542] r9:c0e02c7c r8:e0804000 r7:c0e22a40 r6:dd8ff940 r5:000003eb r4:e080400c
[ 158.277422] [<c01015a0>] (gic_handle_irq) from [<c010d2b0>] (__irq_svc+0x70/0x98)
[ 158.284921] Exception stack(0xdd8ff940 to 0xdd8ff988)
[ 158.290001] f940: 00000001 00000110 00000000 ddfd4800 dda57f00 60070113 00000000 dde98164
[ 158.298204] f960: dde98160 c0e02b18 c0e70b40 dd8ff9ac dd8ff938 dd8ff990 c016ec14 c05e1b00
[ 158.306397] f980: 60070113 ffffffff
[ 158.309899] r10:c0e70b40 r9:dd8fe000 r8:dde98160 r7:dd8ff974 r6:ffffffff r5:60070113
[ 158.317856] r4:c05e1b00
[ 158.320443] [<c05e1a20>] (__usb_hcd_giveback_urb) from [<c05e1bb0>] (usb_giveback_urb_bh+0x90/0xcc)
[ 158.329502] r7:dde98164 r6:dde98184 r5:00000000 r4:dd8ff9b0
[ 158.335278] [<c05e1b20>] (usb_giveback_urb_bh) from [<c0129b4c>] (tasklet_action+0x9c/0x154)
[ 158.343730] r8:00000000 r7:dd8fe000 r6:00000000 r5:dde98190 r4:dde9818c
[ 158.350568] [<c0129ab0>] (tasklet_action) from [<c0129d9c>] (__do_softirq+0x12c/0x298)
[ 158.358499] r10:40000006 r9:c0e02080 r8:00000100 r7:c0e02098 r6:dd8fe000 r5:00000006
[ 158.366454] r4:00000000
[ 158.369032] [<c0129c70>] (__do_softirq) from [<c012a280>] (irq_exit+0xc8/0x13c)
[ 158.376355] r10:00000000 r9:de406000 r8:00000001 r7:00000000 r6:c0e02b18 r5:00000000
[ 158.384310] r4:c0d73fa4
[ 158.386890] [<c012a1b8>] (irq_exit) from [<c017bd2c>] (__handle_domain_irq+0x74/0xe8)
[ 158.394747] [<c017bcb8>] (__handle_domain_irq) from [<c01015f8>] (gic_handle_irq+0x58/0xb8)
[ 158.403113] r9:c0e02c7c r8:e0804000 r7:c0e22a40 r6:dd8ffad0 r5:000003eb r4:e080400c
[ 158.410992] [<c01015a0>] (gic_handle_irq) from [<c010d2b0>] (__irq_svc+0x70/0x98)
[ 158.418491] Exception stack(0xdd8ffad0 to 0xdd8ffb18)
[ 158.423566] fac0: 00000001 00000110 00000000 ddfd4800
[ 158.431768] fae0: a0070013 dde9827c dde7d800 a0070013 00000081 dde98000 dde9827c dd8ffb34
[ 158.439967] fb00: dd8ffac8 dd8ffb20 c016ec14 c090b33c 20070013 ffffffff
[ 158.446594] r10:dde9827c r9:dd8fe000 r8:00000081 r7:dd8ffb04 r6:ffffffff r5:20070013
[ 158.454550] r4:c090b33c
[ 158.457135] [<c090b300>] (_raw_spin_unlock_irqrestore) from [<c05fdf00>] (ehci_urb_enqueue+0xe8/0xdbc)
[ 158.466457] r5:00000000 r4:dd8ffb68
[ 158.470104] [<c05fde18>] (ehci_urb_enqueue) from [<c05e3500>] (usb_hcd_submit_urb+0xb4/0x86c)
[ 158.478643] r10:ddfd9c00 r9:00000003 r8:024000c0 r7:00000000 r6:dde98000 r5:dde7d808
[ 158.486599] r4:dde7d800
[ 158.489180] [<c05e344c>] (usb_hcd_submit_urb) from [<c05e4c54>] (usb_submit_urb+0x2a8/0x4fc)
[ 158.497631] r10:ddfd9c00 r9:00000003 r8:00000204 r7:00000002 r6:dd803c00 r5:024000c0
[ 158.505587] r4:dde7d800
[ 158.508190] [<c05e49ac>] (usb_submit_urb) from [<bf00424c>] (acm_submit_read_urb+0x48/0x8c [cdc_acm])
[ 158.517426] r10:ddfd9c00 r9:00000102 r8:de788800 r7:de788b64 r6:de788800 r5:0000000f
[ 158.525382] r4:024000c0
[ 158.527982] [<bf004204>] (acm_submit_read_urb [cdc_acm]) from [<bf005a34>] (acm_port_activate+0x13c/0x1a4 [cdc_acm])
[ 158.538520] r7:0000000f r6:de788d38 r5:00000000 r4:de78880c
[ 158.544306] [<bf0058f8>] (acm_port_activate [cdc_acm]) from [<c048b944>] (tty_port_open+0x88/0xc8)
[ 158.553281] r9:00000102 r8:c1641b54 r7:de63e8c0 r6:de788930 r5:ddfd9c00 r4:de78880c
[ 158.561171] [<c048b8bc>] (tty_port_open) from [<bf005484>] (acm_tty_open+0x20/0x24 [cdc_acm])
[ 158.569710] r9:00000102 r8:c1641b54 r7:dda4c068 r6:0a600000 r5:de63e8c0 r4:ddfd9c00
[ 158.577608] [<bf005464>] (acm_tty_open [cdc_acm]) from [<c048418c>] (tty_open+0xbc/0x674)
[ 158.585816] [<c04840d0>] (tty_open) from [<c02226d8>] (chrdev_open+0xa4/0x180)
[ 158.593056] r10:dd8ffea8 r9:dd8ffe20 r8:00000000 r7:c0a3bf70 r6:de63e8c0 r5:dda4c068
[ 158.601011] r4:ddeae140
[ 158.603592] [<c0222634>] (chrdev_open) from [<c021b270>] (do_dentry_open+0x1ec/0x310)
[ 158.611436] r7:c0222634 r6:de63e8c8 r5:dda4c068 r4:de63e8c0
[ 158.617212] [<c021b084>] (do_dentry_open) from [<c021c448>] (vfs_open+0x54/0x84)
[ 158.624623] r9:dd8ffe20 r8:00000000 r7:00000102 r6:00000000 r5:de63e8c0 r4:dd8ffea8
[ 158.632511] [<c021c3f4>] (vfs_open) from [<c022c428>] (path_openat+0x384/0xfbc)
[ 158.639836] r6:00000000 r5:dd8fff5c r4:00000000
[ 158.644546] [<c022c0a4>] (path_openat) from [<c022e3e8>] (do_filp_open+0x68/0xcc)
[ 158.652042] r10:00000000 r9:dd8fe000 r8:c0107fc4 r7:00000001 r6:dd8fff5c r5:dd8ffea8
[ 158.659997] r4:00000003
[ 158.662579] [<c022e380>] (do_filp_open) from [<c021c7f0>] (do_sys_open+0x108/0x1c8)
[ 158.670249] r7:00000005 r6:dda86000 r5:ffffff9c r4:00000003
[ 158.676026] [<c021c6e8>] (do_sys_open) from [<c021c8d0>] (SyS_open+0x20/0x24)
[ 158.683176] r9:dd8fe000 r8:c0107fc4 r7:00000005 r6:bea62d84 r5:bea61c08 r4:00037390
[ 158.691063] [<c021c8b0>] (SyS_open) from [<c0107e20>] (ret_fast_syscall+0x0/0x1c)
我试图在异常之前查看这些功能，因为它们已在堆栈跟踪中列出，并进行了一些小的更改以查看可能是问题所在。但是没有成功。 我也将USB堆栈与早期版本的4.6进行了比较，但看不到有什么差异会导致此崩溃。
有人在这个主题上有经验吗，或者可以就继续进行硬件方面提供一些建议？
预先感谢