Re: Help with debugging no-callback problem with IrDA USB dongle (SOLVED!)

Oliver Neukum escribió:
> Am Donnerstag, 3. Mai 2007 18:35 schrieb Alex Villací­s Lasso:
>   
>> /* Coming out of suspend, so reset hardware */
>> static int kingsun_resume(struct usb_interface *intf)
>> {
>>         struct kingsun_cb *kingsun = usb_get_intfdata(intf);
>>
>>         if (kingsun->rx_urb != NULL) usb_submit_urb(kingsun->rx_urb, GFP_KERNEL);
>>         netif_device_attach(kingsun->netdev);
>>
>>         return 0;
>> }
>>     
>
> Do you really want to submit the URB whether the device has been opened
> or not?
>
> 	Regards
> 		Oliver
>
>   
I don't think an URB would be submitted if the device is not opened:

- The code in kingsun_resume() checks for rx_urb != NULL before 
submitting the URB. So your question becomes one of whether rx_urb can 
be not NULL while the device is not opened.
- In kingsun_probe() line 490, rx_urb is assigned NULL shortly after 
allocating a driver structure. After the probe function returns, rx_urb 
is still NULL, since this probe does not allocate any URBs. Therefore, 
if the device is suspended and then resumed right after kingsun_probe(), 
rx_urb is NULL and therefore no URB is submitted. I am assuming here 
that an explicit call to kingsun_net_open() is required to actually open 
the device.
- kingsun_net_open() allocates the URB and (in successful completion) 
leaves the device in the open state. A suspend/resume cycle here will 
submit rx_urb, but the interface is supposed to be opened.
- kingsun_net_close() kills and frees the URBs, and sets their pointers 
to NULL unconditionally. After this, a suspend/resume cycle will find 
rx_urb == NULL and therefore no URB is submitted
- kingsun_disconnect() also kills and frees the URBs, and then sets 
their pointers to NULL, so same argument as in kingsun_net_close()

Am I missing some scenario here?

-- 
perl -e '$x = 2.4; print sprintf("%.0f + %.0f = %.0f\n", $x, $x, $x + $x);'


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