Re: USB lockup on Thinkpad i1300

Alan Cox (alan@lxorguk.ukuu.org.uk)
Sat, 22 Sep 2001 17:50:03 +0100 (BST)


> load usb-ohci. Tracing with kdb shows that the system locks up right
> after executing this: (usb-ohci.c:2137)
>
> /* HC Reset requires max 10 ms delay */
> writel (OHCI_HCR, &ohci->regs->cmdstatus);
>
> Anyone have any idea? The processor apparently never gets to the next
> instruction.
As an experiment stick

unsigned long flags;

save_flags(flags);
cli();
printh("Not dead yet\n");
/* HC ...
..

printk("Writel returned\n");
readl(&ohci->regs->cmdstatus);
printk("Write definitely occurred now\n");
restore_flags(flags);
printk("Ok with IRQ on\n");

Into that piece of code.

That will tell you if for example it is an IRQ storm of some kind.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/