I2C连续频繁读取单字节，读取频朴素的白云，每次读写20次，每次需要读取不同地址单字节。
系统崩溃前多次出现i2c连接超时错误。
一款传感器芯片。
崩溃时间不定，几个小时崩溃，有时几分钟崩溃。cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
cdns-i2c e0004000.i2c: timeout waiting on completion
Unable to handle kernel NULL pointer dereference at virtual address 00000007
pgd = eea2c000
[00000007] *pgd=3ecc5831
Internal error: Oops - BUG: 17 [#1] PREEMPT SMP ARM
Modules linked in: uio_pdrv_genirq
CPU: 0 PID: 1178 Comm: tof-imager-tcp Not tainted 4.9.0-xilinx-v2017.4 #1
Hardware name: 独特的彩虹/p>
task: ef3bf2c0 task.stack: ef34c000
PC is at __fget+0x40/0xa0
pc : [] lr : [] psr: 00030013
sp : ef34df80 ip : 00000001 fp : be90951c
r10: 00000000 r9 : ef34c000 r8 : c0106e24
r7 : ef3e8500 r6 : 00000000 r5 : 00000002 r4 : be909494
r3 : ffffffff r2 : ffffffff r1 : 00000000 r0 : 00000008
Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 18c5387d Table: 2ea2c04a DAC: 00000051
Process tof-imager-tcp (pid: 1178, stack limit = 0xef34c210)
Stack: (0xef34df80 to 0xef34e000)
df80: be909494 b6f0cdf8 0000006e 00000029 c0106e24 c01e7954 be909494 b6f0cdf8
dfa0: 0000006e c0106c60 be909494 b6f0cdf8 00000002 b6ff74c0 00000010 fbad2086
dfc0: be909494 b6f0cdf8 0000006e 00000029 000000e8 be909460 00000020 be90951c
dfe0: 00000044 be90943c b6e2dcc0 b6e954ac 00030010 00000002 00000000 00000000
[] (__fget) from [] (SyS_dup+0x8/0x40)
[] (SyS_dup) from [] (ret_fast_syscall+0x0/0x3c)
Code: e5932000 e1550002 2a000016 e5933004 (e7934000)
---[ end trace 01db90bdf0addaf4 ]---
Unable to handle kernel paging request at virtual address ffffffff
pgd = c0004000
[ffffffff] *pgd=2fffd861, *pte=00000000, *ppte=00000000
Internal error: Oops - BUG: 37 [#2] PREEMPT SMP ARM
Modules linked in: uio_pdrv_genirq
CPU: 0 PID: 1178 Comm: tof-imager-tcp Tainted: G D 4.9.0-xilinx-v2017.4 #1
Hardware name: 独特的彩虹/p>
task: ef3bf2c0 task.stack: ef34c000
PC is at put_files_struct+0x4c/0xd4
pc : [] lr : [] psr: a0030113
sp : ef34dd90 ip : 00000000 fp : c01e6d1c
r10: c0a07da8 r9 : 00000000 r8 : ee4c6140
r7 : 00000000 r6 : ef3bf6e0 r5 : ef3e8500 r4 : 00000000
r3 : ffffffff r2 : 00000000 r1 : 00000000 r0 : ef3e8500
Flags: 勤恳的小丸子 on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 18c5387d Table: 2ea2c04a DAC: 00000051
Process tof-imager-tcp (pid: 1178, stack limit = 0xef34c210)
Stack: (0xef34dd90 to 0xef34e000)
dd80: ef3bf2c0 ee80c8c0 ef3bf6e0 ef34ddb0
dda0: ee80c8f8 00000000 c0a07da8 c011cf74 0000000b ef7d23a0 00000000 00000000
ddc0: c01e6d1c c010a778 ef34c210 0000000b ef7d4400 bf000000 00000008 60030113
dde0: 6580c8c0 32333935 20303030 35353165 32303030 30613220 31303030 35652036
de00: 30333339 28203430 33393765 30303034 00002029 c01901d4 c07d182a 00000007
de20: ef34df30 00000017 ee80c8c0 ef3bf2c0 00000017 c0a4ed0c ee80c8c0 c01171b4
de40: 00000014 c0112f98 600e0013 00000000 000002e7 00000001 ee80c8f8 00000000
de60: 00000000 eea31ed8 ffffff92 00000017 00000007 c0a08734 ef34df30 c0106e24
de80: ef34c000 00000000 be90951c c010128c 000a6dcb 00000002 be90951c c0473cb8
dea0: ef2cb018 a00e0013 ffffff92 eea31ec0 eea31ec0 eea31f40 ef34c000 00000000
dec0: be90951c c01c7eb0 eea31f40 c0475a64 be90947c 00000002 be909474 eea07800
dee0: eea093c0 00000707 be909474 ef34c000 00000000 c0475ec4 eea093c0 00000707
df00: be909474 ee9a02a8 eea093c0 c01dcc84 be909474 c01dce28 00000100 c01e6d1c
df20: 00030013 ffffffff ef34df64 c010adf8 00000008 00000000 ffffffff ffffffff
df40: be909494 00000002 00000000 ef3e8500 c0106e24 ef34c000 00000000 be90951c
df60: 00000001 ef34df80 c01e6d00 c01e6d1c 00030013 ffffffff 00000051 bf000000
df80: be909494 b6f0cdf8 0000006e 00000029 c0106e24 c01e7954 be909494 b6f0cdf8
dfa0: 0000006e c0106c60 be909494 b6f0cdf8 00000002 b6ff74c0 00000010 fbad2086
dfc0: be909494 b6f0cdf8 0000006e 00000029 000000e8 be909460 00000020 be90951c
dfe0: 00000044 be90943c b6e2dcc0 b6e954ac 00030010 00000002 00000000 00000000
[] (put_files_struct) from [] (do_exit+0x3a0/0x860)
[] (do_exit) from [] (die+0x2d0/0x3d4)
[] (die) from [] (__do_kernel_fault.part.0+0x54/0x74)
[] (__do_kernel_fault.part.0) from [] (do_page_fault+0x2c0/0x318)
[] (do_page_fault) from [] (dokwdhmgsjx+0x38/0xb8)
[] (dokwdhmgsjx) from [] (__dabt_svc+0x58/0x80)
Exception stack(0xef34df30 to 0xef34df78)
df20: 00000008 00000000 ffffffff ffffffff
df40: be909494 00000002 00000000 ef3e8500 c0106e24 ef34c000 00000000 be90951c
df60: 00000001 ef34df80 c01e6d00 c01e6d1c 00030013 ffffffff
[] (__dabt_svc) from [] (__fget+0x40/0xa0)
[] (__fget) from [] (SyS_dup+0x8/0x40)
[] (SyS_dup) from [] (ret_fast_syscall+0x0/0x3c)
Code: e1530184 9a000018 e598300c e1a07284 (e7936004)
---[ end trace 01db90bdf0addaf5 ]---
Fixing recursive fault but reboot is needed!
Vivado 2017.4