On Mon, 14 May 2012, Oncaphillis wrote: > <snip> > === proc_do_submiturb uurb->type==1:USBDEVFS_URB_TYPE_INTERRUPT alloc > tb:0xffff880077cfadf0 (512) > === async_completed status==0 length:2/512 e=0 > tb:0xffff880077cfadf0[00][41] last tb:0xffff880079612690[6b][6b] > === free_async free tb:0xffff880077cfadf0 > === proc_do_submiturb uurb->type==1:USBDEVFS_URB_TYPE_INTERRUPT alloc > tb:0xffff880077cfadf0 (512) > === async_completed status==-2 length:0/512 e=0 > tb:0xffff880077cfadf0[6b][6b] last tb:0xffff880077cfadf0[6b][6b] > === free_async free tb:0xffff880077cfadf0 > === proc_do_submiturb uurb->type==3:USBDEVFS_URB_TYPE_BULK alloc > tb:0xffff880079612690 (2) > === async_completed status==0 length:2/2 e=0 > tb:0xffff880079612690[9d][8d] last tb:0xffff880077cfadf0[9d][8d] > === free_async free tb:0xffff880079612690 > ============================================================================= > BUG kmalloc-512 (Not tainted): Poison overwritten > ----------------------------------------------------------------------------- > INFO: 0xffff880077cfadf0-0xffff880077cfadf1. First byte 0x9d instead > of 0x6b > </snip> This gives me an idea for what the problem might be. Basically, ehci-hcd does not do a good job of unlinking interrupt transfers. In drivers/usb/host/ehci-sched.c:intr_deschedule(), you'll find this code: if (list_empty (&qh->qtd_list) || (cpu_to_hc32(ehci, QH_CMASK) & hw->hw_info2) != 0) wait = 2; else wait = 55; /* worst case: 3 * 1024 */ udelay (wait); I suspect the values for "wait" are much too small. The EHCI specification doesn't really say what they should be. Try replacing the entire code snippet above with udelay(1000); and see if that makes any difference. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
