From: "Johannes Erdfelt" <[EMAIL PROTECTED]> > On Wed, May 10, 2000, Dunlap, Randy <[EMAIL PROTECTED]> wrote: > > > > Any results, patches on this subject? > > > > Personally I'd like to see us remove one-shot > > interrupts. It was added to the URB rewrite for > > backwards-compatibility usage for usb_scsi (now > > usb-storage), which no longer uses it. > > > > The suggestion to use a bulk transfer request > > in place of a one-shot interrupt does have a > > downside -- one that I expect Tom would discover > > even if we didn't bring it up. Interrupt transfers > > fall into the guaranteed bandwidth area of USB > > [if usb_submit_urb() doesn't return an error], > > whild bulk transfers have no such guarantee. > > This could make a difference on a device like a > > force-feedback joystick while other guaranteed > > bandwidth transfers are occurring, like large Isoc. > > camera input transfers. > > Good point. I personally hadn't thought about it that way. Agreed with Johannes. Also, if you use bulks but really mean interrupts, it might confuse people down the road. > I'd still like to see interval == 0 mean a one shot interrupt, > automatically unlinked after execution. This is a *really* neat feature for the only few (one?) people using interrupt out. It removes any kind of state machines and asynchronous uncertainties when you are done with a few transfers. Works like a charm on Johannes' uhci, BTW, and with a little help also in Georg's usb-uhci. > How an HC driver implements it is up to them. > > This would ensure that bandwidth (when it is implemented correctly) is > counted correctly. Again, I have to agree. I don't know enough *really in-depth* to make an educated decision. So, consider my input as a "halfway educated guess" ;-) Thanks for keeping at it, ..tom --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
