~ # Unable to handle kernel NULL pointer dereference at virtual address         
0000000c
pgd = c0004000                                                                  
[0000000c] *pgd=00000000                                                        
Internal error: Oops: 807 [#1]                                                  
Modules linked in: usbserial pehci hal_ep93xx i2s                               
CPU: 0                                                                          
PC is at pehci_hcd_atl_worker+0x368/0x830 [pehci]                               
LR is at pehci_hcd_atl_worker+0x350/0x830 [pehci]                               
pc : [<bf012924>]    lr : [<bf01290c>]    Not tainted                           
sp : c0225e4c  ip : c0225e4c  fp : c0225ec4                                     
r10: 00000000  r9 : ffffffff  r8 : 00000000                                     
r7 : c59129c0  r6 : c5f91400  r5 : bf017400  r4 : c5fdb620                      
r3 : 00000004  r2 : c0225e5c  r1 : c5fdb1a0  r0 : bf017294                      
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  Segment kernel                      
Control: C000717F  Table: C5BCC000  DAC: 0000001D                               
Process swapper (pid: 0, stack limit = 0xc02241b8)                              
Stack: (0xc0225e4c to 0xc0226000)


    28e0:       e24b2064        sub     r2, fp, #100    ; 0x64
    28e4:       e582c000        str     ip, [r2]
    28e8:       e24bc064        sub     ip, fp, #100    ; 0x64
    28ec:       e59c2000        ldr     r2, [ip]
    28f0:       e1a01801        lsl     r1, r1, #16
    28f4:       e18ec003        orr     ip, lr, r3
    28f8:       e24be050        sub     lr, fp, #80     ; 0x50
    28fc:       e5960144        ldr     r0, [r6, #324]
    2900:       e1a01821        lsr     r1, r1, #16
    2904:       e58ec000        str     ip, [lr]
    2908:       ebfffffe        bl      0 <isp1761_reg_write32>
    290c:       e59f04cc        ldr     r0, [pc, #1228] ; 2de0 
<pehci_hcd_atl_worker+0x824>
    2910:       e24b2068        sub     r2, fp, #104    ; 0x68
    2914:       e5d03001        ldrb    r3, [r0, #1]
    2918:       e5921000        ldr     r1, [r2]
    291c:       e2433001        sub     r3, r3, #1      ; 0x1
    2920:       e5c03001        strb    r3, [r0, #1]
    2924:       e588a00c        str     sl, [r8, #12]
    2928:       e51b003c        ldr     r0, [fp, #-60]
    292c:       eb000809        bl      202c 
<pehci_hcd_update_error_status>
    2930:       e51b003c        ldr     r0, [fp, #-60]


        /*clear the corrosponding mask register*/
	ormask &= ~td_ptd_map->ptd_bitmap;
        isp1761_reg_write32(hcd->dev, hcd->regs.atl_irq_mask_or,ormask);

	ptd_map_buff->active_ptds--;

        urbpriv->timeout = 0;

        /*take care of errors*/
	pehci_hcd_update_error_status(qha->td_info4, urb);
	/*halted, need to finish all the transfer on this endpoint*/
        if(qha->td_info4 & PTD_STATUS_HALTED){
            qtd->state |= QTD_STATE_LAST;

            donemap &= ~td_ptd_map->ptd_bitmap;
            /*in case pending*/
            ptd_map_buff->pending_ptd_bitmap &= ~td_ptd_map->ptd_bitmap;
            /*in case of halt, next transfer will start with toggle
              zero,USB speck, 5.8.5*/
            qh->datatoggle =  td_ptd_map->datatoggle = 0;