Alan, Sorry for my later reply mail. I'm busying for another usb client driver issue. Now i will be focus on this usb host transfer issue. And just like you mentioned i should send 3 urbs in prob function, do i need to build 3 urbs by using FILL_BULK_URB function? If yes, 3 complete_callback_function will be create or not? If no, do you think i should build 3 urbs by using usb_alloc_urb function? Could you give me some simple sample codes for operations? Thanks a lot!
Merry Christmas~~ 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 ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
