Hello

I am trying to run io-usb on  an omap2420 (arm6) under 6.4.0 m7 and it is getting stuck (and hogging the cpu) inside a 
pthread_mutex_lock(). Getting a core file with dumper shows that one of the threads is spinning in arm6 specific code in
  _mux_smp_cmpxchg(). 


separate dumps report pc: 
pc             0x103024c        0x103024c <_mux_smp_cmpxchg+44>
pc             0x1030254        0x1030254 <_mux_smp_cmpxchg+52>
pc             0x103024c        0x103024c <_mux_smp_cmpxchg+44>

disassemble:
Dump of assembler code for function _mux_smp_cmpxchg:
0x01030220 <_mux_smp_cmpxchg+0>:        push    {r10, lr}
0x01030224 <_mux_smp_cmpxchg+4>:        ldr     r10, [pc, #92]  ; 0x1030288 <_mux_smp_cmpxchg+104>
0x01030228 <_mux_smp_cmpxchg+8>:        ldr     r12, [pc, #92]  ; 0x103028c <_mux_smp_cmpxchg+108>
0x0103022c <_mux_smp_cmpxchg+12>:       add     r10, pc, r10
0x01030230 <_mux_smp_cmpxchg+16>:       ldr     r12, [r10, r12]
0x01030234 <_mux_smp_cmpxchg+20>:       ldr     r12, [r12]
0x01030238 <_mux_smp_cmpxchg+24>:       tst     r12, #2 ; 0x2
0x0103023c <_mux_smp_cmpxchg+28>:       beq     0x1030264 <_mux_smp_cmpxchg+68>
0x01030240 <_mux_smp_cmpxchg+32>:       mcr     15, 0, r0, cr7, cr10, {5}
0x01030244 <_mux_smp_cmpxchg+36>:       mov     r12, r0
0x01030248 <_mux_smp_cmpxchg+40>:       ldrex   r0, [r12]
0x0103024c <_mux_smp_cmpxchg+44>:       teq     r0, r1
0x01030250 <_mux_smp_cmpxchg+48>:       strexeq r3, r2, [r12]
0x01030254 <_mux_smp_cmpxchg+52>:       teqeq   r3, #1  ; 0x1
0x01030258 <_mux_smp_cmpxchg+56>:       beq     0x1030248 <_mux_smp_cmpxchg+40>
0x0103025c <_mux_smp_cmpxchg+60>:       mcr     15, 0, r0, cr7, cr10, {5}
0x01030260 <_mux_smp_cmpxchg+64>:       pop     {r10, pc}
0x01030264 <_mux_smp_cmpxchg+68>:       add     r12, pc, #4     ; 0x4
0x01030268 <_mux_smp_cmpxchg+72>:       add     lr, pc, #12     ; 0xc
0x0103026c <_mux_smp_cmpxchg+76>:       sub     sp, sp, #1      ; 0x1
0x01030270 <_mux_smp_cmpxchg+80>:       ldr     r3, [r0]
0x01030274 <_mux_smp_cmpxchg+84>:       teq     r3, r1
0x01030278 <_mux_smp_cmpxchg+88>:       streq   r2, [r0]
0x0103027c <_mux_smp_cmpxchg+92>:       add     sp, sp, #1      ; 0x1
0x01030280 <_mux_smp_cmpxchg+96>:       mov     r0, r3
0x01030284 <_mux_smp_cmpxchg+100>:      pop     {r10, pc}
0x01030288 <_mux_smp_cmpxchg+104>:      andeq   r0, r4, r8, ror #19
0x0103028c <_mux_smp_cmpxchg+108>:      strheq  r0, [r0], -r4
End of assembler dump.