>>No.  Send the first 3 URBs from the probe function.  Don't wait for them
>>to complete, just send them all immediately.  Then send the remaining URBs 
>>from the completion callback.
OK, i will try it.

>>I didn't realize you were using 2.4.x.  You may have to set the 
>>URB_QUEUE_BULK flag in order to queue more than one bulk URB at a time.
I set the flag = USB_ASYNC_UNLINK, hehe, i will modify it to URB_QUEUE_BULK

Thank you very much!

Levis

-----Original Message-----
From: Alan Stern [mailto:[EMAIL PROTECTED]
Sent: Saturday, November 13, 2004 3:49 AM
To: Xu Levis-Q16136
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: RE: An usb host transfer speed issue, could anybodies help me or give 
me some advice?


On Fri, 12 Nov 2004, Xu Levis-Q16136 wrote:

> Alan,
> Thanks for your great help!
> I used Linux_2.4.20, usb OHC(Intel XScale PX27x), USB1.1 full speed. The
> device is my cell phone(Intel XScale PX255).
> 
> For Bulk_IN transfer model, we can send the first IN_URB from prob func.
> just like my codes. And then we can send the next IN_URB in the
> complete_callback func. is it right?

No.  Send the first 3 URBs from the probe function.  Don't wait for them
to complete, just send them all immediately.  Then send the remaining URBs
from the completion callback.

> if we send the next IN_URB before the last IN_URB complete_callback,
> will we happen an "urb already in use" issue? Anyway, i will try your
> suggestions.

I didn't realize you were using 2.4.x.  You may have to set the 
URB_QUEUE_BULK flag in order to queue more than one bulk URB at a time.

Alan Stern


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