urb unlink hanging

[anton wilson <anton.wilson@camotion.com>]

I'm having a problem where the kernel is freezing when the function 
sohci_unlink_urb is attempting to shedule_timeout(timeout). The exact point 
in the kerneL where it freezes is in add_timer(&timer) after the spinlock is 
locked. 

I attempted to fix this problem by setting the USB_ASYNC_UNLINK flag when the 
urbs are created in the probe function. This stops the freezing of the 
kernel, but my computer starts making a continuous humming noise after the 
calls to sohci_unlink_urb. I'm not sure why my computer is humming, but I 
know something is not going right.

I'm using a 2.4.17 kernel.


Any suggestions?
 




The urbs are set up this way:


        if( (purb = (purb_t)usb_alloc_urb(NUMBER_OF_PACKETS)) == NULL )
        {
            MSG("Error allocating URB.\n");
            goto p1;    //de-allocate buffer
        }

        context->urbs[i] = purb ;
        memset(purb, 0, sizeof(urb_t));

        //
        //fill in the URB
        //
        purb->dev                    = context->rasid_dev;
        purb->transfer_flags         = USB_ISO_ASAP | USB_ASYNC_UNLINK;
        purb->number_of_packets      = NUMBER_OF_PACKETS;   //1
        purb->context                = context;             //pointer to the  
        purb->transfer_buffer_length = TRANSFER_BUFFER_LENGTH; //64
        if (i < SND_URB_POOL_SIZE)                          //setup a send URB
        {
            purb->pipe     = context->snd_pipe;
            purb->interval = ISOC_SND_INTERVAL;  //1
            purb->timeout  = SND_TIMEOUT;        //10000
            purb->complete = rasid_snd_complete; 
        }

        else                                               //setup a receive
        {
            purb->pipe     = context->rcv_pipe;
            purb->interval = ISOC_RCV_INTERVAL; //1
            purb->timeout  = RCV_TIMEOUT; //10000
            purb->complete = rasid_rcv_complete;
        }
        for (j = 0; j < NUMBER_OF_PACKETS; j++)
        {
            purb->iso_frame_desc[j].offset = (TRANSFER_PACKET_SIZE) * j ;
            purb->iso_frame_desc[j].length = TRANSFER_PACKET_SIZE ;
        }

        if(!(purb->transfer_buffer = (char*)kmalloc(TRANSFER_BUFFER_LENGTH, 
GFP_KERNEL)) )        {
            MSG("Out of memory while allocating I/O buffer.\n");
            goto p1;        //de-allocate entire driver context
        }
-- 

Anton Wilson
Camotion
Software Development
-- 
Camotion
Software Development
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