Problems with FTDI adapter and evbarm devices

[Jason Mitchell <jmitchel%bigjar.com@localhost>]

Hello,

There something that causes frequent crashes when using an FTDI USB to 
serial converter with a Raspberry Pi 3B (and maybe other evbarm 
devices). The easiest way to reproduce this bug is to:


1) Insert an FTDI cable
2) Run minimum and connect to the ucom port associated with the FTDI adapter
3) Remove the FTDI cable

I could NOT make this happen with an aarch64 machine (Libre LePotato), 
but I did not extensively test.

The console output is below. I caused the crash twice to make sure it 
was reproducible.

Could someone let me know what the next steps are to troubleshoot this?

Thanks,

Jason M.


#### First Time ####

stan:~# [ 185921.3922827] ucom0: detached

[ 185921.3922827] uvm_fault(0x80762dd0, ffffe000, 1) -> e
[ 185921.4022863] uftdi0: detached
[ 185921.4022863] Fatal kernel mode data abort: 'Translation Fault (S)'
[ 185921.4122886] uftdi0: at uhub2trapframe: 0x812afb78
[ 185921.4122886] FSR=00000005, FAR= port 3 (addr 4) disconnected
[ 185921.4222888] fffffffc, spsr=20070013
[ 185921.4222888] r0 =fffffff0, r1 =80422ae0, r2 =fffffff0, r3 =fffffff0
[ 185921.4322887] r4 =fffffff0, r5 =8112dfd0, r6 =8112dfd0, r7 =807c92e0
[ 185921.4322887] r8 =00000000, r9 =b87929a0, r10=80460ab0, r11=812afc24
[ 185921.4422919] r12=812afc28, ssp=812afbc8, slr=802ca63c, pc =802ca4c0

Stopped in pid 2790.1 (minicom) at netbsd:mutex_oncpu.part.0+0x4: ldr
r0, [r2, #0x00c]
db{3}> c
panic: Fatal abort
[ 185922.1910811] cpu3: Begin traceback...
[ 185922.1910811] 0x812afa44: netbsd:db_panic+0x14
[ 185922.1910811] 0x812afa5c: netbsd:vpanic+0x194
[ 185922.2010848] 0x812afa74: netbsd:snprintf
[ 185922.2010848] 0x812afaac: netbsd:dab_fatal+0x168
[ 185922.2110825] 0x812afb74: netbsd:data_abort_handler+0x110
[ 185922.2110825] 0x812afc24: netbsd:address_exception_entry+0x5c
[ 185922.2210826] 0x812afc94: netbsd:ucomopen+0x58
[ 185922.2210826] 0x812afd0c: netbsd:spec_open+0x20c
[ 185922.2310842] 0x812afd34: netbsd:VOP_OPEN+0x44
[ 185922.2310842] 0x812afe0c: netbsd:vn_open+0x200
[ 185922.2410844] 0x812afe8c: netbsd:do_open+0xac
[ 185922.2410844] 0x812afec4: netbsd:do_sys_openat+0xa4
[ 185922.2510843] 0x812afeec: netbsd:sys_open+0x38
[ 185922.2510843] 0x812affac: netbsd:syscall+0x12c
[ 185922.2610849] cpu3: End traceback...

[ 185922.2610849] dump to dev 92,1 not possible

####      ####


#### Second Time ####

[ 145.4967800] ucom0: detached

[ 145.4967800] uvm_fault(0x80756210, ffffe000, 1) -> e
[ 145.4967800] uftdi0: detached
[ 145.4967800] Fatal kernel mode data abort: 'Translation Fault (S)'
[ 145.5094179] uftdi0: at uhub1trapframe: 0xb8227b78
[ 145.5183235] FSR=00000005, FAR=fffffffc, spsr=20070013
[ 145.5183235]  port 3r0 =fffffff0, r1 =80422b88, r2 =fffffff0, r3 =fffffff0
[ 145.5183235]  (addr 5) disconnected
[ 145.5183235] r4 =fffffff0, r5 =baf3e7d0, r6 =baf3e7d0, r7 =807bc720
[ 145.5383259] r8 =00000000, r9 =ba569740, r10=80460c2c, r11=b8227c24
[ 145.5383259] r12=b8227c28, ssp=b8227bc8, slr=802ca744, pc =802ca5c8

Stopped in pid 568.1 (minicom) at netbsd:mutex_oncpu.part.0+0x4: ldr
r0, [r2, #0x00c]
db{3}> c
panic: Fatal abort
[ 146.4740935] cpu3: Begin traceback...
[ 146.4740935] 0xb8227a44: netbsd:db_panic+0x14
[ 146.4740935] 0xb8227a5c: netbsd:vpanic+0x194
[ 146.4840941] 0xb8227a74: netbsd:snprintf
[ 146.4940950] 0xb8227aac: netbsd:dab_fatal+0x168
[ 146.4940950] 0xb8227b74: netbsd:data_abort_handler+0x110
[ 146.5040954] 0xb8227c24: netbsd:address_exception_entry+0x5c
[ 146.5040954] 0xb8227c94: netbsd:ucomopen+0x58
[ 146.5140953] 0xb8227d0c: netbsd:spec_open+0x20c
[ 146.5140953] 0xb8227d34: netbsd:VOP_OPEN+0x44
[ 146.5240966] 0xb8227e0c: netbsd:vn_open+0x200
[ 146.5240966] 0xb8227e8c: netbsd:do_open+0xac
[ 146.5340960] 0xb8227ec4: netbsd:do_sys_openat+0xa4
[ 146.5340960] 0xb8227eec: netbsd:sys_open+0x38
[ 146.5340960] 0xb8227fac: netbsd:syscall+0x12c
[ 146.5440970] cpu3: End traceback...

[ 146.5440970] dump to dev 92,1 not possible
[ 146.9341106] uhub1: port 2 reset failed


####    ####