4.7 vs 4.8
----------

Checked the same code under 4.7. linaro 4.7-2013.04-20130415 does not have
this problem. Note instruction at 0x8030602c that does store relative $r7
and it updates $r7. Whereas in 4.8 similar instruction comes at address 
0x80319548 which is after instruction that corrupts saved on stack register.

4.7 
---

(gdb) disassemble xhci_check_trb_in_td_math
Dump of assembler code for function xhci_check_trb_in_td_math:
   0x8030600c <+0>:	stmdb	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr} <---
   0x80306010 <+4>:	sub	sp, #436	; 0x1b4  <----------------------
   0x80306012 <+6>:	push	{lr}                     <----------------------
   0x80306014 <+8>:	bl	0x8000cdcc <__gnu_mcount_nc> <------------------
   0x80306018 <+12>:	add	r7, sp, #432	; 0x1b0  <----------------------
   0x8030601a <+14>:	mov	r9, r0
   0x8030601c <+16>:	ldr	r1, [r0, #116]	; 0x74
   0x8030601e <+18>:	add	r3, sp, #176	; 0xb0
   0x80306020 <+20>:	ldr	r2, [r0, #96]	; 0x60
   0x80306022 <+22>:	movs	r0, #0
   0x80306024 <+24>:	movs	r4, #0
   0x80306026 <+26>:	ldr.w	r8, [r1]
   0x8030602a <+30>:	movs	r1, #0
   0x8030602c <+32>:	strd	r0, r1, [r7, #-384]!	; 0x180 <--------------
   0x80306030 <+36>:	mov	r6, r4
   0x80306032 <+38>:	ldr	r2, [r2, #0]
   0x80306034 <+40>:	ldr.w	r1, [r8]
   0x80306038 <+44>:	str	r4, [sp, #40]	; 0x28
   0x8030603a <+46>:	ldrd	r10, r11, [r2, #8]
   0x8030603e <+50>:	add.w	r0, r1, #1008	; 0x3f0
   0x80306042 <+54>:	str	r1, [sp, #28]
   0x80306044 <+56>:	str	r0, [sp, #44]	; 0x2c
   0x80306046 <+58>:	ldrd	r0, r1, [r8, #8]
   0x8030604a <+62>:	strd	r10, r11, [sp, #32]
   0x8030604e <+66>:	ldrd	r10, r11, [r8, #8]
   0x80306052 <+70>:	adds	r1, #64	; 0x40
   0x80306054 <+72>:	ldr	r5, [r2, #0]
   0x80306056 <+74>:	adc.w	r0, r0, #0
   0x8030605a <+78>:	str.w	r8, [r3]
   0x8030605e <+82>:	subs.w	r11, r11, #16
   0x80306062 <+86>:	strd	r0, r1, [r3, #112]	; 0x70
   0x80306066 <+90>:	ldrd	r0, r1, [r8, #8]
   0x8030606a <+94>:	adc.w	r10, r10, #4294967295
   0x8030606e <+98>:	strd	r10, r11, [r7, #16] <-------------------------


4.8
---

(gdb) disassemble xhci_check_trb_in_td_math
Dump of assembler code for function xhci_check_trb_in_td_math:
   0x803194e4 <+0>:	stmdb	sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr} <---
   0x803194e8 <+4>:	sub	sp, #444	; 0x1bc  <----------------------
   0x803194ea <+6>:	push	{lr}                     <----------------------
   0x803194ec <+8>:	bl	0x8000cc8c <__gnu_mcount_nc> <------------------
   0x803194f0 <+12>:	mov	r9, r0
   0x803194f2 <+14>:	movs	r5, #0
   0x803194f4 <+16>:	ldr	r0, [r0, #116]	; 0x74
   0x803194f6 <+18>:	mov	r11, r5
   0x803194f8 <+20>:	ldr.w	r1, [r9, #96]	; 0x60
   0x803194fc <+24>:	add.w	lr, sp, #184	; 0xb8
   0x80319500 <+28>:	str	r5, [sp, #32]
   0x80319502 <+30>:	add	r7, sp, #440	; 0x1b8  <----------------------
   0x80319504 <+32>:	ldr.w	r8, [r0]
   0x80319508 <+36>:	ldr	r0, [r1, #0]
   0x8031950a <+38>:	str	r5, [sp, #36]	; 0x24
   0x8031950c <+40>:	str	r5, [sp, #52]	; 0x34
   0x8031950e <+42>:	ldrd	r4, r5, [r8, #8]
   0x80319512 <+46>:	ldr	r2, [r0, #0]
   0x80319514 <+48>:	ldr.w	r10, [r8]
   0x80319518 <+52>:	adds.w	r3, r5, #64	; 0x40
   0x8031951c <+56>:	str.w	r8, [lr]
   0x80319520 <+60>:	str.w	r2, [lr, #68]	; 0x44
   0x80319524 <+64>:	adc.w	r2, r4, #0
   0x80319528 <+68>:	strd	r2, r3, [lr, #112]	; 0x70
   0x8031952c <+72>:	subs.w	r3, r5, #16
   0x80319530 <+76>:	adc.w	r2, r4, #4294967295
   0x80319534 <+80>:	add.w	r6, r10, #1008	; 0x3f0
   0x80319538 <+84>:	strd	r2, r3, [r7, #16] <-----------------------------
   0x8031953c <+88>:	ldrd	r2, r3, [sp, #32]
   0x80319540 <+92>:	str	r6, [sp, #48]	; 0x30
   0x80319542 <+94>:	str.w	r6, [lr, #8]
   0x80319546 <+98>:	mov	r6, r11
   0x80319548 <+100>:	strd	r2, r3, [r7, #-384]!	; 0x180 <---------------
   0x8031954c <+104>:	movw	r3, #12272	; 0x2ff0
   0x80319550 <+108>:	movt	r3, #32859	; 0x805b