On Sat, 7 Jul 2007, Oliver Neukum wrote: > Am Samstag, 7. Juli 2007 schrieb Alan Stern: > > > This brings me to an idea. > > > Is it possible to accept the next scsi request while the current request > > > is > > > being executed? That way, when the first request finishes, the URBs > > > could be retained if they are needed right away and otherwise freed. > > > > It's _possible_, but why go through all that work? Just keep the URBs > > allocated permanently. They don't take up much space compared with > > UHCI's TDs. > > I was hoping to keep everything, not just the URBs.
Fine, then keep everything. For OHCI and EHCI the additional overhead will be comparable to that of the URBs. This is essentially what you wanted to do with your preallocation anyway, right? As a minor point: We should allow for dynamic allocation in situations where the transfer length exceeds the preallocated size. After the transfer completes the dynamically-allocated memory can be released just as it is now. And if the dynamic allocation fails, we simply fall back to doing the transfer in multiple bunches using only the resources already available. Alan Stern ------------------------------------------------------------------------- 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/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
