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USB on AU1550

To: linux-mips@linux-mips.org
Subject: USB on AU1550
From: Jay Monkman <jtm@smoothsmoothie.com>
Date: Wed, 28 Sep 2005 15:52:41 -0500
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
User-agent: Debian Thunderbird 1.0.2 (X11/20050817)
I'm trying to get USB working on my AU1550 board, and I'm getting an error I
don't understand. I've searched the web and the mailing list archives, but
haven't found anything relevant.

I'm using 2.6.12, in big-endian mode.

After the kernel comes up, I plug in a USB flash drive and get this on the 
console:
    au1xxx-ohci au1xxx-ohci.0: GetStatus roothub.portstatus [1] = 0x00010101 CSC
PPS CCS
    hub 1-0:1.0: port 2, status 0101, change 0001, 12 Mb/s
    hub 1-0:1.0: debounce: port 2: total 100ms stable 100ms status 0x101
    au1xxx-ohci au1xxx-ohci.0: GetStatus roothub.portstatus [1] = 0x00100103
PRSC PPS PES CCS
    usb 1-2: new full speed USB device using au1xxx-ohci and address 2
    au1xxx-ohci au1xxx-ohci.0: Unlink after no-IRQ?  Controller is probably
using the wrong IRQ.


This is the comment in the code before that printk():
        /* IRQ setup can easily be broken so that USB controllers
         * never get completion IRQs ... maybe even the ones we need to
         * finish unlinking the initial failed usb_set_address()
         * or device descriptor fetch.
         */
        if (!hcd->saw_irq && hcd->self.root_hub != urb->dev) {
                dev_warn (hcd->self.controller, "Unlink after no-IRQ?  "
                        "Controller is probably using the wrong IRQ."
                        "\n");
                hcd->saw_irq = 1;
        }

When I get here in the code, hcd->saw_irq is 0, and it looks like this function
(hcd_unlink_urb()) is getting called from run_timer_softirq(), so I guess I'm
not getting the interrupt. However, immediately after returning, usb_hcd_irq()
does get called. As far as I can tell, the interrupt gets serviced as soon as
hcd_unlink_urb returns.

It looks like the timer function causing this is timeout_kill(), initialized in
usb_start_wait_urb() which has this comment:
        // Starts urb and waits for completion or timeout
        // note that this call is NOT interruptible, while
        // many device driver i/o requests should be interruptible



Can anyone point me in the right direction to get this working?

Thanks.

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