Re: USB lockup on Thinkpad i1300

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Sat Sep 22 2001 - 11:50:03 EST


> 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.
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This archive was generated by hypermail 2b29 : Sun Sep 23 2001 - 21:00:49 EST