IMX6串口0造成崩溃的问题

yiliu · ‎01-25-2016

我们有客户项目在使用串口时遇到死机问题，具体情况描述如下：

客户使用串口ttymxc0是正常的，但考虑到有些客户需要用到串口，需保留这个作为调试用，所以在开机时候在设置环境变量串口做了更改。这样配置后造成系统崩溃，先前客户在IMX53也这样用过但是正常的，想请教下是什么原因？谢谢！

（已让工程师用官网镜像实验，同样会有这个问题）下面是客户邮件内容：

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李工，林工：

您们好!

关于/dev/ttymxc0 出现死机的问题。我用了官方的包也是一样会死。

我们用的版本及其硬件信息如下：android4.3

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # getprop ro.build.fingerprint

Freescale/sabresd_6dq/sabresd_6dq:4.3/1.1.0-rc4/20131206:user/dev-keys

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # cat /proc/version

Linux version 3.0.35 (tennycent@tennycent-li) (gcc version 4.6.x-google 20120106 (prerelease) (GCC) ) #280 SMP PREEMPT Sun Jan 24 16:37:58 CST 2016

root@sabresd_6dq:/ #

一、设置 console=ttymxc0 （这样是正常的）

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # cat /proc/cmdline

no_console_suspend console=ttymxc0,115200 root=/dev/mmcblk0p1 init=/init video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666,bpp=32 ldb=sin0 video=mxcfb1:off video=mxcfb2:off fbmem=10M fb0base=0x17b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale

root@sabresd_6dq:/ #

130|root@sabresd_6dq:/ # echo 0123 > /dev/ttymxc0

0123

root@sabresd_6dq:/ #

二、设置 console=ttymxc1 （我们是要设置为console=null，这样可以理由ttymxc0这个串口）

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # cat /proc/cmdline

no_console_suspend console=ttymxc1,115200 root=/dev/mmcblk0p1 init=/init video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666,bpp=32 ldb=sin0 video=mxcfb1:off video=mxcfb2:off fbmem=10M fb0base=0x17b00000 vmalloc=400M androidboot.console=ttymxc1 androidboot.hardware=freescale

root@sabresd_6dq:/ #

root@sabresd_6dq:/ # echo 0123 >/dev/ttymxc0

root@sabresd_6dq:/ # mmc0: Timeout waiting for hardware interrupt.

sdhci: =========== REGISTER DUMP (mmc0)===========

sdhci: Sys addr: 0x26802000 | Version: 0x00000002

sdhci: Blk size: 0x00000200 | Blk cnt: 0x00000000

sdhci: Argument: 0x00000000 | Trn mode: 0x00000000

sdhci: Present: 0xfffd8088 | Host ctl: 0x00000021

sdhci: Power: 0x0000000d | Blk gap: 0x00000000

sdhci: Wake-up: 0x00000000 | Clock: 0x0000001f

sdhci: Timeout: 0x00000000 | Int stat: 0x00000000

sdhci: Int enab: 0x107f000b | Sig enab: 0x107f000b

sdhci: AC12 err: 0x00000000 | Slot int: 0x00000003

sdhci: Caps: 0x07eb0000 | Caps_1: 0x00000007

sdhci: Cmd: 0x00000c1b | Max curr: 0x00ffffff

sdhci: Host ctl2: 0x00000004

sdhci: ===========================================

INFO: rcu_preempt_state detected stall on CPU 0 (t=6000 jiffies)

Backtrace for cpu 0 (current):

[<c0115fc4>] (unwind_backtrace+0x0/0x138) from [<c0114e48>] (smp_send_all_cpu_b)

[<c0114e48>] (smp_send_all_cpu_backtrace+0x60/0xdc) from [<c019a3f8>] (__rcu_pe)

INFO: rcu_preempt_state detected stalls on CPUs/tasks: { 0} (detected by 3, t=6)

[<c019a3f8>] (__rcu_pending+0x144/0x3c0) from [<c019afa4>] (rcu_check_callbacks)

[<c019afa4>] (rcu_check_callbacks+0x13c/0x204) from [<c015f534>] (update_proces)

[<c015f534>] (update_process_times+0x38/0x68) from [<c017eb38>] (tick_sched_tim)

[<c017eb38>] (tick_sched_timer+0x80/0xe4) from [<c01725a0>] (__run_hrtimer+0x80)

[<c01725a0>] (__run_hrtimer+0x80/0x2c0) from [<c017349c>] (hrtimer_interrupt+0x)

[<c017349c>] (hrtimer_interrupt+0x118/0x294) from [<c01081b0>] (do_local_timer+)

[<c01081b0>] (do_local_timer+0x6c/0x90) from [<c010e34c>] (__irq_svc+0x4c/0xe8)

Exception stack(0xc09cbec8 to 0xc09cbf10)

bec0: 00000000 c0a55f40 00000000 c0a55f40 00000002 c09e07d0

bee0: c09ca000 00000000 c0a55f60 c09ca000 00000000 00000000 c0115750 c09cbf10

bf00: c0156e84 c01567d4 200f0113 ffffffff

[<c010e34c>] (__irq_svc+0x4c/0xe8) from [<c01567d4>] (__do_softirq+0x60/0x25c)

[<c01567d4>] (__do_softirq+0x60/0x25c) from [<c0156e84>] (irq_exit+0x98/0xa0)

[<c0156e84>] (irq_exit+0x98/0xa0) from [<c01081b4>] (do_local_timer+0x70/0x90)

[<c01081b4>] (do_local_timer+0x70/0x90) from [<c010e34c>] (__irq_svc+0x4c/0xe8)

Exception stack(0xc09cbf68 to 0xc09cbfb0)

bf60: c0a57888 800f0093 00000001 00000000 c09ca000 c0a4f304

bf80: c077b2f4 c09e87fc 1000406a 412fc09a 00000000 00000000 00000000 c09cbfb0

bfa0: c011e264 c010f468 400f0013 ffffffff

[<c010e34c>] (__irq_svc+0x4c/0xe8) from [<c010f468>] (default_idle+0x24/0x28)

[<c010f468>] (default_idle+0x24/0x28) from [<c010f778>] (cpu_idle+0xc8/0x108)

[<c010f778>] (cpu_idle+0xc8/0x108) from [<c00088bc>] (start_kernel+0x29c/0x2ec)

[<c00088bc>] (start_kernel+0x29c/0x2ec) from [<10008040>] (0x10008040)

sending IPI to all other CPUs:

IPI backtrace for cpu 1

Pid: 0, comm: swapper

CPU: 1 Not tainted (3.0.35 #280)

PC is at cpu_idle+0x7c/0x108

LR is at cpu_idle+0xb8/0x108

pc : [<c010f72c>] lr : [<c010f768>] psr: 200e0013

sp : d6067fe0 ip : 00000001 fp : 00000000

r10: 00000000 r9 : 412fc09a r8 : 1000406a

r7 : c09e87fc r6 : c077b2f4 r5 : c0a4f304 r4 : d6066000

r3 : 00000000 r2 : c0a578b0 r1 : 00000001 r0 : 00000001

Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel

Control: 10c53c7d Table: 226a404a DAC: 00000015

PC: 0xc010f6ac:

f6ac e12fff1e e92d40f8 f1080040 e59f60e8 e1a0300d e59f50e4 e3c34d7f e59f70e0

f6cc e3c4403f e3a00001 eb0108e1 e3a00001 eb01bda7 e5943000 e3130002 1a000012

f6ec e5943014 e5961000 e3530000 e283001f e203201f b1a03000 e1a032c3 e7913103

f70c e1a03233 e3130001 0a00001c f10c0080 e5953000 e3530000 0a00000e f1080080

f72c e5943000 e3130002 0affffec eb01beae e3a00002 eb0108c6 e5943004 e2433001

f74c e5843004 eb199adb e5943004 e2833001 e5843004 eaffffda eb01b99c e3500000

f76c 1affffed e5973004 e12fff33 e10f3000 e3130080 1a000003 f1080080 eaffffd4

f78c eb1935f0 eaffffe0 e59f0018 e3a010fa eb0101e7 f1080080 eaffffcd c077b2f4

LR: 0xc010f6e8:

f6e8 1a000012 e5943014 e5961000 e3530000 e283001f e203201f b1a03000 e1a032c3

f708 e7913103 e1a03233 e3130001 0a00001c f10c0080 e5953000 e3530000 0a00000e

f728 f1080080 e5943000 e3130002 0affffec eb01beae e3a00002 eb0108c6 e5943004

f748 e2433001 e5843004 eb199adb e5943004 e2833001 e5843004 eaffffda eb01b99c

f768 e3500000 1affffed e5973004 e12fff33 e10f3000 e3130080 1a000003 f1080080

f788 eaffffd4 eb1935f0 eaffffe0 e59f0018 e3a010fa eb0101e7 f1080080 eaffffcd

f7a8 c077b2f4 c0a4f304 c09e87fc c08c0964 e1a0200d e3c23d7f e3c3303f e5932004

f7c8 e2822001 e5832004 ea0015c9 e92d4008 ebfffff6 eafffffe e92d4008 ebfffff3

SP: 0xd6067f60:

7f60 d6067f98 c0a4f4b0 00000000 c010fbd4 c09e07d0 c010836c ffffffff f2a00100

7f80 00000007 00000002 00000001 d6066000 00000000 c010e34c 00000001 00000001

7fa0 c0a578b0 00000000 d6066000 c0a4f304 c077b2f4 c09e87fc 1000406a 412fc09a

7fc0 00000000 00000000 00000001 d6067fe0 c010f768 c010f72c 200e0013 ffffffff

7fe0 c076c79c 2606806a 00000015 10c03c7d c0a4f4b8 1076c7b4 55189cc0 36b00017

8000 00000000 00000001 00000000 d60460a0 c09fbdd0 00000001 00000015 d60460a0

8020 c13ec320 00000000 d6068000 58f17a78 d6046580 d604634c d6069fac d6069ef8

8040 c0775c54 00000000 00000000 00000000 00000000 00000000 00000000 00000000

R2: 0xc0a57830:

7830 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

7850 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

7870 00000000 00000000 00000000 00000000 d60090c0 00000001 00000000 00000000

7890 c09fe5b8 00000000 11550680 00000018 00989680 00000000 00000000 00000000

78b0 00000002 00000000 00000000 00000000 00000000 00000006 c09fa860 00000001

78d0 00000000 00000000 00000000 00000000 10bc7000 00000018 00000000 00000000

78f0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

7910 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

R4: 0xd6065f80:

5f80 13318200 d6064000 c0a55f40 00000001 c077b2f4 00000000 00000000 00000002

5fa0 00000000 c0156b14 d6031f24 00000001 c01569d0 00000013 00000000 00000000

5fc0 00000000 c016e928 c010f408 00000000 00000001 00000000 00000000 00000000

5fe0 d6065fe0 d6065fe0 d6031f24 c016e8a8 c010f408 c010f408 402023a4 8885186a

6000 00000000 00000004 00000000 d6046580 c09fbdd0 00000001 00000015 d6046580

6020 c13ec320 d636e420 d6066000 ab1f3ee0 d67bb520 00000001 d6067fdc d6067f28

6040 c0775c54 00000000 00000000 00000000 00000000 00000000 00000000 00000000

6060 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

R5: 0xc0a4f284:

f284 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

f2a4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

f2c4 00000000 00000000 00000000 00000000 000392fb 00000000 00000001 00000000

f2e4 d6f4c1b0 00000000 00000000 00000000 00000003 00000000 00000000 00000000

f304 00000000 c012e624 00000000 00000000 c09e84b4 00000000 00000000 00000000

f324 00000000 00063015 c011cadc 006c3776 00000000 c08c61d8 00000000 00000000

f344 c01567d4 200f0113 bf005b84 c0188e70 800f0193 0c7a0000 400b5266 200b0030

f364 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000001

R6: 0xc077b274:

b274 00000004 00000008 00000010 00000020 00000040 00000080 00000100 00000200

b294 00000400 00000800 00001000 00002000 00004000 00008000 00010000 00020000

b2b4 00040000 00080000 00100000 00200000 00400000 00800000 01000000 02000000

b2d4 04000000 08000000 10000000 20000000 40000000 80000000 c09dfb20 c09dfb18

b2f4 c09dfb14 c09dfb1c 0000000f 00000000 c08cac1c 00000001 c08cac20 00000002

b314 c08cac28 00000003 c08cac30 00000004 c08cac38 00000005 c08cac40 00000006

b334 c08cac50 00000007 c08cac58 00000008 c08cac60 00000009 c08cac68 ffffffff

b354 00000000 00000063 63657622 2075253d 7463615b 3d6e6f69 225d7325 4552202c

R7: 0xc09e877c:

877c 00000000 c010d624 00000000 c010d4d4 00000000 c010d45c 00000000 c010d434

879c 00000000 c010d0d4 00000000 c010cf5c 00000000 c010c884 00000000 00000000

87bc 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

87dc 00000000 00000000 00000000 00000000 00000000 c010e800 10c53c7d 10c53c7d

87fc 00000068 c010f444 c010f53c c09e8944 c09e8824 0fffffff 07f001f0 00000020

881c 00000000 c011064c c09e8808 c09e8840 0000ffff 0000de01 00000020 00000020

883c c011064c c09e8824 c09e8944 0000ffff 0000f7f0 00000020 00000020 c01105f4

885c 00000000 50000000 00000000 011e0000 00000008 00000000 00000000 00000000

IPI backtrace for cpu 2

Pid: 0, comm: swapper

CPU: 2 Not tainted (3.0.35 #280)

PC is at cpu_idle+0x7c/0x108

LR is at cpu_idle+0xb8/0x108

pc : [<c010f72c>] lr : [<c010f768>] psr: 200f0013

sp : d6073fe0 ip : 00000002 fp : 00000000

r10: 00000000 r9 : 412fc09a r8 : 1000406a

r7 : c09e87fc r6 : c077b2f4 r5 : c0a4f304 r4 : d6072000

r3 : 00000000 r2 : c0a578b0 r1 : 00000002 r0 : 00000001

Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel

Control: 10c53c7d Table: 26f0804a DAC: 00000015