Re: question on ehci's memory needs
David Brownell <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Friday 29 June 2007, Oliver Neukum wrote: > Hi, > > I am trying to calculate worst cases memory requirements of EHCI. > For bulk transfers it seems to me that you need size/16384 (rounded up) > qtd and one qh. Is it really that easy? ISTR, yes. And interrupt transfers are the same. > What about the other transfer types? Control transfers are like bulk/intr, plus one more qtd. ISO is ISTR urb->number_of_packets plus a dummy qh. What do you count? ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel